Added docs folder and in it we added instructions of how to generate documentation (#192)

* Added Readme.md for generating docs

* Updated Readme.md

* Updated readme.md

* Updated readme changed regex

Author: mnoman09

docs/readme.md

@@ -0,0 +1,14 @@
+# Generate Code Documentation
+### Steps	
+* Checkout **master** branch.
+* Open project in **IntelliJ**.
+* Go to **Tools -> Generate JavaDoc**
+* Make sure **Generate JavaDoc scope -> Custom Scope** is checked.
+* Click on three dotted icon to make custom scope.
+* Give name **Custom_Docs**.
+* Copy and paste following regex: **`!*..internal..*&&!test:*..*&&!lib:*..*`** into **Pattern** and click **OK**.
+* Uncheck **Include test sources**.
+* Select **Output Directory**.
+* Click **OK**.
+* This will generate HTML documentation in given **Output Directory**.
+* Browse **Output Directory/index.html** in browser.