Add examples to readthedocs output

[mithro]

It would be awesome to have the examples listed in the LUNA readthedocs documentation -- even if it is just a table with a short description and a link to the directory in github.

[TomKeddie]

@ktemkin I know you write awesome documentation but surely you're overloaded at this point. Would you like me to take this little one? Easy to understand usage examples would be great for the campaign.

Please indicate where in the tree you'd like this to appear and I'll get onto it. My thoughts would be to mimic the examples tree under docs unless you'd prefer to keep the docs with the examples (at your preference).