Enhanced rendering for bug description and suggestedfix.

[karlcow]

Following a discussion on IRC with @hallvors we were wondering how the presentation could be improved for the simplebug for the pre tag in description and suggestedfix.

Currently we use a pre tag because the markup is essentially plain text with a bit of code. We could try to convert on the fly but that would probably break some of the earlier comments. We can't edit again new comments.

A feature to explore is when the commenter is sure to have entered markdown markup (basically 4 spaces for code. Links yumminess, etc.), s/he could had the md tag in addition to description and suggestedfix. That way we could make a shinier version.

[karlcow]

An example of a possible dynamic rendering.

I used mdown because the tagging system doesn't accept 2 characters only and mdn could be confused with the developer documentation in Mozilla world.

Also, for boilerplates texts, we could directly process them without pre tags because we already know what they are. Maybe I should open another issue for these.

[miketaylr]

If you check out the new version, I've changed the font of description and suggested fix--I think it looks much nicer (and not terrible for code block). Perhaps that counts as a half fix.