Add content for CLI (#2609)

* Update readme.md

* Update readme.md

* Update readme.md

* Update content/roadmaps/102-devops/content/102-managing-servers/101-live-in-terminal/readme.md

* Update content/roadmaps/102-devops/content/102-managing-servers/101-live-in-terminal/readme.md

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

content/roadmaps/102-devops/content/102-managing-servers/101-live-in-terminal/readme.md

@@ -1 +1,6 @@
-# Live in terminal
+# Live in terminal
+
+A terminal is simply a text-based interface to the computer, it is use to interact with your computer system via CLI (command line interface)
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://en.wikipedia.org/wiki/Command-line_interface'>What is CLI?</BadgeLink>