[Docs] add 2 sidebars to documentation

[HassanBahati]

Currently there is one sidebar to the left of the documentation. For neater organization;

1. On the left, we have a sidebar that has all links linking to the other inner pages of the documentation
2. On the right, we have a sidebar that highlights main contents of a given page.

ps: This may be with an exception of the home page to have totally no sidebars

This below Image of the current sidebar to be on the right sidebar