Linkify links in trigger values (resolves #5)

Signed-off-by: Jan Krüger <jk@jk.gs>
Add favicon

This has been sitting in the live env for a while and I only just noticed
that it's not in the repo yet. Whoops!

Signed-off-by: Jan Krüger <jk@jk.gs>
Updates to "documentation"

Document:

* @p suffix to send triggers to the person being addressed, via private
  message
* .graph and .digraph
* .version

Signed-off-by: Jan Krüger <jk@jk.gs>