Use issue forms to augment existing templates

[alice-i-cecile]

As just announced, issue forms allow us to create smarter templates with form elements for our issues (and presumably PRs.

This could be useful for reducing friction and improving clarity of the existing templates. Some initial ideas for implementation:

• many fields are optional (e.g. OS on bug reports): this can be better communicated using
• Bevy version can be selected from a drop-down (each release, latest main, other)
• we could hook up some auto-labelling to form input; platform is the obvious suggestion. It's not clear that this is worthwhile though.

(cc @NathanSWard, @mockersf, @TheRawMeatball to continue discussion from Discord)

[alice-i-cecile]

So, I'm personally of the opinion that these are Fine™️; they may be a nice quality of life improvement (especially for optional fields) but I don't think they solve any serious problem that we have right now.

As long as "blank issue" still exists, we should be able to have an escape hatch for one-off issues like this one, which ought to reduce frustration for more advanced users.