Handle comment delimiters not on same line as 'todo' keyword

[klein0r]

Comments are defined like this:

..
    _This: is a comment!

..
    [and] this!

..
    this:: too!

..
    |even| this:: !

Additionally, support for https://www.sphinx-doc.org/en/master/usage/extensions/todo.html would be awesome

.. todo::
     This is a todo

[alstr]

Interesting, thanks for the suggestion! It would definitely be good to add this; PR requests are always welcome for new languages, and they're relatively easy to do. This does look a little more complicated than the standard comment syntax. For one, at the moment if the comment delimiter is not on the same line as the 'todo' keyword/title, it won't get picked up, but that is something I am hoping to improve.

[alstr]

I've done some experimentation and the challenges to adding this at the moment are:

• The lowercase todo (added support in latest commit)
• The double colon after todo (at the moment it thinks the second colon is the title)
• The fact that the formatting is somewhat unique; it isn't like a normal line comment as there is no comment delimiter on the second line, but it isn't a block comment as there's no closing tag.

The second one is an easy fix; the third is a bit more involved.

[silopolis]

We'd surely be a bunch to welcome this addition!
Thanks for taking care of it :)

[alstr]

The next version should support this style:

.. todo:: This is my issue title.

However, the below presents challenges I can't accommodate yet:

.. todo::

   This is another issue title and it
   breaks across multiple lines.

Mainly because the action doesn't associate those two lines as comments. This is something fundamental to how the action works, so no easy workaround currently.