The markdown syntax for comments is
<!---
your comment goes here
and here
-->
When I create a new pull request from a branch, I get the following boilerplate comment in the opening paragraph
<!-- If this pull request fixes an issue please indicate which issue by typing "Fixes #NNNN" below.>
It needs a `--` before the `>` at the end of the line, otherwise nothing that is typed below is seen (since it is part of an unterminated comment.
Is that under our control or is that a Github issue?
/c