[DOCUMENTATION] Add initial docs & issue/PR templates

[YummYume]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context. List any dependencies that are required for this change.

No issue linked.

Type of change

Please add any relevant information to the type of change you've made.

• [ ] 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 not work as expected)
• [x] This change requires a documentation update (or is a documentation update)
• [ ] HIGH IMPORTANCE (requires a fast merging)

Has This Been Tested?

Please describe the tests that you ran to verify your changes. It is way more likely for a PR to be merged and approved with successful tests.

• [ ] Yes, I ran tests (describe below)
• [ ] No, I did not include any test
• [x] No test is needed for this change

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules

Browser compatibility (optional)

Which browser was this tested on?

• [ ] Chrome
• [ ] Firefox
• [ ] Opera
• [ ] Safari
• [ ] Edge
• [ ] Samsung Internet
• [ ] Others (specify)

[YummYume]

GitHub automatically closed this PR after a forced push (wasn't using the same email as my GPG key) for some reason. I made a new PR.