Quote review suggestions in comments

[apiraino]

This looks like an innocent cosmetic change now but it become critical when we will implement the new review assignment.

In case a pull request review cannot be assigned (for any reason), the triagebot will post a comment on GitHub. The text of the comment does not quote correctly the "r?" wording, example "Use r? to specify someone else to assign.".

That could trigger an infinite loop where the words "r? to" are interpreted by the triagebot receiving the webhook after posting that command.

Quoting with markdown will prevent this loop.

I am not sure this patch solves 100% of the all cases but it should cover most of them.

r? @jackh726

[rustbot]

Error: Parsing assign command in comment failed: ...' example "' | error: specify user to assign to at >| 'Use r? to '...

Parsing assign command in comment failed: ...' to' | error: specify user to assign to at >| '" are inte'...

Please file an issue on GitHub at triagebot if there's a problem with this bot, or reach out on #t-infra on Zulip.

[rustbot]

Error: Parsing assign command in comment failed: ...' example "' | error: specify user to assign to at >| 'Use r? to '...

Parsing assign command in comment failed: ...' to' | error: specify user to assign to at >| '" are inte'...

Please file an issue on GitHub at triagebot if there's a problem with this bot, or reach out on #t-infra on Zulip.

[Mark-Simulacrum]

We should already be ignoring any messages from triagebot for command parsing, but extra quoting shouldn't hurt.