Customize Task UUID Symbol

[shfattig]

Currently, TaskWiki shows the UUID of tracked tasks by appending #{uuid} to the end of the todo item. Unfortunately this conflicts with tools which use # to denote tags, with a massive list of uuid junk presented on tag searches.

It would be very helpful if the user could deconflict this syntax by customizing the symbol used to something other than # -- perhaps ${uuid} or %{uuid} or |{uuid}

[shfattig]

I've implemented a working solution that handles (almost) every symbol and created a pull request #437. There are a few things that I'd love @maintainers help and insight on, so please review and comment!