Add issue checker

[ndrezn]

Closes #3508

Primarily to help the core team review incoming community PRs and keep track of changes.

GHA can be found in: https://github.com/plotly/pr-issue-checker

[github-actions]

Thank you for your contribution to Dash! 🎉

[AnnMarieW]

What does the error message say if there is no linked issue? Lots of people don’t know you have to use a magic word before the issue number like fixes or closes. And it needs to be in the first issue message block, otherwise GH doesn’t automatically close the issue when it’s merged.

[ndrezn]

@AnnMarieW the failure message looks like this:

[camdecoster]

There might be some kinks to work out, but it seems like we should turn it on and see how it goes.

[ndrezn]

@T4rk1n could I get a ✅ ?