docs: feature request and bug report issue templates added

[phisco]

Description of your changes

Adding missing bug and feature request issue templates, inspired by Crossplane's ones.

I have:

• [x] Read and followed Upbound's contribution process.
• [x] Run make reviewable to ensure this PR is ready for review.
• [x] Added backport release-x.y labels to auto-backport this PR, as appropriate.

How has this code been tested

N.A.