chore: split issue templates, move them to ISSUE_TEMPLATES folder

[hirotasoshu]

Resolves #753

Description

This PR upgrades issue templates (current issue template is not being used by github). I also split issue templates to bug_report and feature_request with adding a little "sugar", i.e. auto-labeling and title template (the same way I did in django-axes)

Motivation and Context

I think motivation is pretty clear:)

How Has This Been Tested?

You can look how it works at django-axes repo

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[moggers87]

Thanks for taking the time to do this. Other than the label on the feature request template I think this is good to be merged.

[moggers87]

👍