Add-on dialogue: Markdown formatting removed

[ajdapretnar]

Add-on dialogue in v 3.23.1

Add-on dialogue on current master

Somewhere we have lost markdown formatting. @markotoplak is in favour of removing markdown altogether. I like it, but if no markdown is a better option, I'm fine with it also.

What we need to do is either make the dialogue render as .md or rewrite add-on descriptions to have a nicer format.

[janezd]

I like markdown, too. Unless it complicates our lives. Previous version looks nicer.