Add support for readme on main page

[Nemo157]

A lot of projects have code samples rendered in their main readme that reference other modules, would be nice if these were linked as well.

Probably should add support for within other rendered code elements as well at the same time.

I'll add some links to examples later.

[lxe]

I just ran into this scenario. Definitely a +1

[Nemo157]

https://github.com/tadeuszwojcik/supertest-chai/ has an example section using some modules.