All vue pages now request `/nav` to get a JSON array of navigation
instead of relying on the Go template to have the nav built in. This
cleans up all of the crufty `{{ "{{ thing }}" }}` that was making it
hard to wriet vue.
This also paves the way to using the new Go resource embedding so that
the pages don't need to be wrapped in Go files.
* URLs can be translated to slack/discord compatible
* Emojy have a connector-specific translation configuration
* Advent of Code plugin respects emojy and URLs
* Config can be wrapped in `` for JSON