fix formatting

[depial]

Follow-up to PR #1100

• Adds two more spaces to nested lists (bringing it to four spaces) in about.md and introduction.md.
• Changes the markdown headings to bold font in instructions.md.

[depial]

I would have preferred the inner lists remained unnumbered, but I'll take it!

[depial]

One thing that is kind of odd... My solution says it's Processing and has been since we merged PR 1100, even after going in and rerunning the tests manually (although I haven't submitted another iteration). Do you see anything of the sort?

[colinleach]

I'm not having any problems like this. Feels like another random glitch?

[depial]

I assume it is, so if you don't see this on the website for mine, then I think we should be okay. I was just worried that the site somehow got stuck in an infinite loop or something and was wasting compute time.

[depial]

Actually, now I see the processing wheel for another solution:

Are you seeing this? Apparently, the solution was posted in the last hour or so.

It's been taking a long time to run the tests, so I figure there must be something else going on (Jiki related maybe?)

[depial]

I've "fixed" mine in the community solutions by submitting a new iteration (5), but iteration 4 remains "Processing"...

In any case, I'm calling it a day!