Template Lookup: A Guide

@pamubay Thanks! I originally had the sidebar always open, but I found that it took too much space.

@HenrySkup I’m not sure that’s necessarily a good idea, which is why I haven’t worked on making this a PR to the docs.

It feels (for me) like it would clutter the docs to have too many examples. Plenty of people have been able to create sites with Hugo just with the docs as it stands now, so I would assume that it is sufficient (and sufficiently effective) for most of Hugo’s audience.

As an alternative, however: perhaps a link to either this discussion or the demo itself. I could spin this into its own project (currently it’s bundled with my other tips n tricks post).