Add root index for documentation

Signed-off-by: Ayan Sinha Mahapatra <ayansmahapatra@gmail.com>

Author: AyanSinhaMahapatra

docs/source/index.rst

@@ -7,32 +7,64 @@ Guide
 .. toctree::
    :maxdepth: 2
 
+   getting-started/index
+   cli-reference/index
+   plugins/index
+   tutorials/index
+   how-to-guides/index
+   explanations/index
+   contribute/index
+   misc/index
    license
 
+Getting Started
+***************
+
+.. toctree::
+   :maxdepth: 2
+
+   scancode-toolkit/getting-started/newcomer
 
 Tutorial Documents
 ==================
 
 Tutorial documents provide specific instructions to help you get started.
 
+.. toctree::
+   :maxdepth: 2
+
+   scancode-toolkit/tutorials/index
 
 How-To Documents
 ================
 
 How-To documents explain how to accomplish specific tasks.
 
+.. toctree::
+   :maxdepth: 2
+
+   scancode-toolkit/how-to-guides/index
 
 Reference Documents
 ===================
 
-Reference documents describe application concepts in depth.
+Reference documents describe the Command Line options, and application concepts in depth.
 
+.. toctree::
+   :maxdepth: 2
+
+   scancode-toolkit/cli-reference/index
 
 Discussion Documents
 ====================
 
-Discussion documents provide insights into integration of the application into your own software
-development life cycle.
+Discussion documents provide insights into how scancode works, and integration of the application
+into your own software development life cycle.
+
+.. toctree::
+   :maxdepth: 2
+
+   scancode-toolkit/explanations/index
 
 
 Indices and Tables
@@ -41,3 +73,7 @@ Indices and Tables
 * :ref:`genindex`
 * :ref:`modindex`
 * :ref:`search`
+
+.. _improve_docs:
+
+.. include::  /scancode-toolkit/rst_snippets/improve_docs.rst