Add md line break to stale-issues.yml
I just read https://gitlab.com/gitlab-org/gitlab-ce/issues/60192 and thought I found a typo. Turned out it was not, but an appearance of https://gitlab.com/gitlab-org/gitlab-ce/issues/57809. Since md does not apply single line breaks that formatting did not get applied and thus the wrong looking result. I changed that now adding punctuation and two spaces at the end of the line which applies a single line break in md. I hope this is the correct way.
There might be other occurrences of this problem, so it might be worth to check other places (in this and other files) as well.
Edited by Lin Jen-Shin