Social Pane customization in Dynamics 365

Hello Folks,

I'm novice to Dynamics CRM.

Can you please let me know at what extent we can modify Social Pane in Dynamics 365 ? All I wanted to know, is it possible to show Sales Literature in the Social Pane as we can see KB Records entity as a tab. Moreover, can we add any custom entity to social pane ?

If yes then how and if not then why? 

Thanks in advance! :)