Pull request types in template on GitHub

[Rainer Müller]

Hello,

our GitHub pull request template [1] contains the following snippet
which is used by the macportsbot to assign the corresponding label to it.

###### Type(s)
<!-- update (title contains ": U(u)pdate to"), submission (new Portfile)
and CVE Identifiers are auto-detected, replace [ ] with [x] to select -->
- [ ] bugfix
- [ ] enhancement
- [ ] security fix

However, GitHub interpretes this as a list of tasks. This means that
with that list alone with one entry selected, the pull request will be
displayed with the note "1 of 3" and a progress bar next to it in the
list of pull requests.

Could we switch to a different syntax to avoid that?

Rainer

[1]
https://github.com/macports/macports-ports/blob/master/.github/PULL_REQUEST_TEMPLATE.md