Adding issue templates to Github

[spjuhel]

Changes proposed in this PR:

• Adding issue templates to the GitHub platform

PR Author Checklist

• [x] Read the Contribution Guide
• [x] Correct target branch selected (if unsure, select develop)
• [x] Descriptive pull request title added
• [x] Source branch up-to-date with target branch
• [x] Documentation updated
• [x] Tests updated
• [x] Tests passing
• [x] No new linter issues
• [ ] Changelog updated

PR Reviewer Checklist

• [ ] Read the Contribution Guide
• [ ] CLIMADA Reviewer Checklist passed
• [ ] Tests passing
• [ ] No new linter issues

[spjuhel]

The doc on this: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository

It is also possible to create issue forms: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository#creating-issue-forms

[chahank]

Fully agree! Thanks @spjuhel. I just proposed one small addition to help unexperienced users to find the information on their operating system and their Python version. Otherwise, I would propose to merge.