Add content about APIs (#2546)

* added readme.md file

(#1839) [https://github.com/kamranahmedse/developer-roadmap/issues/1839] Please look at my PR!

* Update content/roadmaps/107-nodejs/content/107-nodejs-apis/readme.md

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

content/roadmaps/107-nodejs/content/107-nodejs-apis/readme.md

@@ -1 +1,6 @@
-# Nodejs apis
+# APIs
+
+API is the acronym for Application Programming Interface, which is a software intermediary that allows two applications to talk to each other.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://aws.amazon.com/what-is/api/'>What is an API?</BadgeLink>