Update to GitHub Issue Forms

[JacobCoffee]

Note: This repo is for the Python devguide. If you are requesting an
enhancement for the Python language or CPython interpreter,
then the CPython issue tracker is better
suited for this report: https://github.com/python/cpython/issues

Describe the enhancement or feature you'd like
A clear and concise description of what you want to happen.

When opening an issue you are greeted with this blob of text:

Details

but since the templates were made GitHub have introduced Issue Forms
which, if we did a direct conversion would look like this:

Details

It would be nice to implement this. I would be up for working through changes and have a draft PR:
#1414

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.
Continue using current style

Additional context
Add any other context or screenshots about the feature request here.

We get the benefit of section context, and markdown for the special admonition and text, without having to add it into a place that people need to delete (or can even edit directly)

[JacobCoffee]

Some prior art is https://github.com/python/pythondotorg/issues/new/choose, where I implemented this across all issue types in python/pythondotorg#2571

I also added a config.yml that adds quicklinks to help lost people find their way. If there is interest I would be up for opening an issue and PR for that as well

Details

[ezio-melotti]

I like the idea and left a few comments on the draft PR!

[I initially misread and though this was about the cpython repo and transferred the issue to core-workflow, and now moved it back here 🙃]

[encukou]

Thank you for the suggestion and PR!
Since it's been merged, I'll close the issue.