Implement server side pages for learn/subject/chapter

[M-ZubairAhmed]

We currently are managing change of pages inside the guide with local state, which makes sharing a particular chapter impossible. Also side bar implementation is heavy as both sidebar and right content has to keep track of the state. By assigning a particular route for each chapter makes it easy and decouples the sidebar and right content section.

[vinaypuppal]

Okay I will try to implement it this weekend