[ENH] Link API Reference to source

[genedan]

It's possible to link the API reference in the docs to the source code on Github. For example, in pandas and other pydata projects, there is a link to the source near the header:

I've found out how to do this, the main thing you need is a function within the docs conf.py file:

https://github.com/genedan/TmVal/blob/69166dc91129b1a1760bfae2a73faa56ccd7aedc/docs/conf.py#L51-L102