Fix typos (#4500)

- Fixed a typo
- Fixed the title of the freecodecamp link

src/data/roadmaps/nodejs/content/104-nodejs-async-programming/102-promises.md

@@ -1,6 +1,6 @@
 # Promises
 
-A promise is commonly defined as a proxy for a value that will eventually become available
+A promise is commonly defined as a proxy for a value that will eventually become available.
 Asynchronous functions use promise behind the scenes, so understanding how promises work is fundamental to understanding how "async" and "await" works.
 Once a promise has been called, it will start in a pending state. This means that the calling function continues executing, while the promise is pending until it resolves, giving the calling function whatever data was being requested.
 
@@ -13,5 +13,5 @@ Visit the following resources to learn more:
 
 - [Promise Methods](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)
 - [Official Website](https://www.promisejs.org/)
-- [Official Website](https://www.freecodecamp.org/news/javascript-promises-for-beginners/)
+- [JavaScript Promises for Beginners](https://www.freecodecamp.org/news/javascript-promises-for-beginners/)
 - [Asynchronous JavaScript - Promises](https://www.youtube.com/watch?v=a_8nrslImo4/)