Added content to Javascript This keyword (#1990)

* blank spaces removed in existing files

* Added content to javascript this keyword

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/100-function-borrowing.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/100-function-borrowing.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/100-function-borrowing.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/102-this-in-a-function.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/103-using-this-alone.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/104-this-in-event-handlers.md

* Update content/roadmaps/106-javascript/content/111-javascript-this-keyword/105-this-in-arrow-functions.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/106-javascript/content/100-javascript-introduction/100-what-is-javascript.md

@@ -10,4 +10,3 @@ JavaScript, often abbreviated JS, is a programming language that is one of the c
 <BadgeLink badgeText='Read' colorScheme="yellow" href='https://exploringjs.com/'>Exploring JS: JavaScript books for programmers</BadgeLink>
 <BadgeLink badgeText='Watch' href='https://youtu.be/hdI2bqOjy3c?t=2'>JavaScript Crash Course for Beginners</BadgeLink>
 <BadgeLink badgeText='Watch' href='https://youtu.be/P7t13SGytRk?t=22'>Build a Netflix Landing Page Clone with HTML, CSS & JS</BadgeLink>
-

content/roadmaps/106-javascript/content/100-javascript-introduction/101-history-of-javascript.md

@@ -5,6 +5,3 @@ JavaScript was initially created by Brendan Eich of NetScape and was first annou
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://roadmap.sh/guides/history-of-javascript'>Brief History of JavaScript</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://dev.to/iarchitsharma/the-history-of-javascript-5e98'>The History of JavaScript</BadgeLink>
-
-
-

content/roadmaps/106-javascript/content/100-javascript-introduction/102-javascript-versions.md

@@ -5,5 +5,3 @@ JavaScript was invented by Brendan Eich, and in 1997 and became an ECMA standard
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.educative.io/blog/javascript-versions-history'>JavaScript Versions: How JavaScript has changed over the years</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://roadmap.sh/guides/history-of-javascript'>Brief History of JavaScript</BadgeLink>
-
-

content/roadmaps/106-javascript/content/100-javascript-introduction/103-how-to-run-javascript.md

@@ -6,6 +6,3 @@ JavaScript can be run in the browser by including the external script file using
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.digitalocean.com/community/tutorials/how-to-add-javascript-to-html'>How To Add JavaScript to HTML</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.digitalocean.com/community/tutorials/how-to-write-your-first-javascript-program'>How To Write Your First JavaScript Program</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.digitalocean.com/community/tutorials/how-to-use-the-javascript-developer-console'>How To Use the JavaScript Developer Console</BadgeLink>
-
-
-

content/roadmaps/106-javascript/content/101-javascript-variables/100-variable-declarations/100-var.md

@@ -8,6 +8,3 @@ The var statement declares a function-scoped or globally-scoped variable, option
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/js/js_variables.asp'>JavaScript Variables - W3Schools</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.youtube.com/watch?v=6UAKBYpUC-Y'>Declaring Variables without Var, Let, Const - What Would Happen?</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.geeksforgeeks.org/how-to-declare-variables-in-different-ways-in-javascript/'>How to declare variables in different ways in JavaScript?</BadgeLink>
-
-
-

content/roadmaps/106-javascript/content/101-javascript-variables/102-naming-rules.md

@@ -7,5 +7,3 @@ A variable name should accurately identify your variable. When you create good v
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.dummies.com/article/technology/programming-web-design/javascript/naming-javascript-variables-142522/'>Naming JavaScript Variables</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.robinwieruch.de/javascript-naming-conventions/'>JavaScript Naming Conventions</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://google.github.io/styleguide/jsguide.html'>Google JavaScript Style Guide</BadgeLink>
-
-

content/roadmaps/106-javascript/content/111-javascript-this-keyword/100-function-borrowing.md

@@ -2,4 +2,5 @@
 
 Function borrowing allows us to use the methods of one object on a different object without having to make a copy of that method and maintain it in two separate places. It is accomplished through the use of `.call()`, `.apply()`, or `.bind()`, all of which exist to explicitly set this on the method we are borrowing.
 
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme="yellow" badgeText="Read" href="https://medium.com/@ensallee/function-borrowing-in-javascript-4bd671e9d7b4">Function borrowing</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/102-this-in-a-function.md

@@ -1 +1,8 @@
-# This in a function
+# this in a function
+
+The keyword `this` when used in a function refers to the global object.
+
+*Note: in a browser window the global object is the `window` object.*
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/js/js_this.asp'>this in a function</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/103-using-this-alone.md

@@ -1 +1,8 @@
 # Using this alone
+
+The keyword `this` when used alone refers to the global object.
+
+*Note: in a browser window the global object is the `window` object.*
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/js/js_this.asp'>this Alone</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/104-this-in-event-handlers.md

@@ -1 +1,6 @@
-# This in event handlers
+# this in event handlers
+
+The keyword `this` when used in an event handler refers to the element that received the event.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/js/js_this.asp'>this in Event handlers</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/105-this-in-arrow-functions.md

@@ -1 +1,6 @@
-# This in arrow functions
+# this in arrow functions
+
+The keyword `this` when used in an arrow function refers to the parent object.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://stackoverflow.com/questions/66518020/javascript-this-keyword-and-arrow-function'>this keyword and arrow function</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/106-explicit-binding.md

@@ -1,11 +1,7 @@
 # Explicit binding
 
-In this method, you can force a function to use a certain object as its this. Explicit Binding can be applied using call(), apply(), and bind().
-
-call(): Pass in the required object as the first parameter during the function call. The actual parameters are passed after the object.
-
-apply(): Similar to call() with a difference in the way the actual arguments are passed. Here, the actual arguments are passed as an array.
-
-bind(): In this method, you create a new function with a fixed this. These types of functions created using bind() are commonly known as bound functions.
+Explicit binding is when you use the `call` or `apply` methods to explicitly set the value of `this` in a function. Explicit Binding can be applied using `call()`, `apply()`, and `bind()`.
 
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://medium.com/swlh/javascript-this-ac28f8e0f65d'>Explicit Binding</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://medium.com/@msinha2801/explicit-binding-rule-for-this-keyword-in-js-712405b0a11'>Explicit Binding rule for this keyword</BadgeLink>

content/roadmaps/106-javascript/content/111-javascript-this-keyword/readme.md

@@ -11,4 +11,3 @@ In JavaScript, the `this` keyword is a little different compared to other langua
 
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/js/js_this.asp'>The JavaScript `this` Keyword</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this'>This Keyword</BadgeLink>
-