Update issue and pull request templates

[steff456]

This PR is part of #514

This PR,

• Update issue template for bug reports
• Update issue template for feature requests
• Adds an issue template for general issues
• Adds a pull request template

[costrouc]

LGTM. @trallard do you have any feedback on these templates I'm assuming that these templates are modeled after other issue templates we've used.

[pavithraes]

@steff456 Thank you for this PR! I've added a couple of small suggestions, but it looks great overall. I'll approve, so you can feel-free to merge when ready. :)

[trallard]

Thanks, @steff456, I have requested some changes, also we need to add a config.yml file to direct people to the templates and the documentation. And to disallow blank issues.

[steff456]

@trallard there's already a config.yml under .github/ISSUE_TEMPLATE/ folder that disallows blank issues. Let me know if there's anything extra this PR needs!

[trallard]

Yes that config only disallows the blank issue.
Can you also link to the conda-store docs from there and add the templates?

If you need a reference see the Nebari config

[trallard]

I just pushed some changes directly and can merge as-is I do not want this to linger any more