Support more markdown in comments

[corsacca]

We support links. test [text](https://google.com) renders like:

Lets add:

• bold: **bold** or __bold__
• italics: *italics*
• lists:

- one
- two
- three

or

* one
* two
* three

And:

• Images: ![image](https://github.com/DiscipleTools/disciple-tools-theme/assets/24901539/7d51d61d-07ea-414f-8a46-ce83b994bd93)

See https://www.markdownguide.org/basic-syntax

Not supported by markdown:

• Underline