Change regressions and bug reports to use form

[alexec]

Too many user files incomplete bug reports, or have not done any basic diagnosis of the issue.

We could try https://beyondco.de/blog/github-issue-forms to reduce this problem and reduce the number of bug reports.

[alexec]

@caelan-io would you be interested in doing this?

[caelan-io]

Yes, happy to take this on after ArgoCon 👍