Github Wiki Cleanup

## Dependencies
- Added to #771, will work on this once other engineering efforts to improve code accessibility are complete.

### Overview
Need to cleanup the project wiki on GitHub to make it a more complete resource for engineer onboarding and documentation.

### Action Items
Reference how other teams are using the wiki to facilitate onboarding of new team-members and define specific workflows for pull request approval. Update our wiki so that most questions can be addressed by it.

### Resources/Instructions
Onboarding examples:
- https://github.com/hackforla/website/wiki/Web-Developer
- https://github.com/hackforla/internship/wiki/Project-Introduction-for-Interns
- https://github.com/hackforla/.github/wiki

Process Example:
- https://github.com/hackforla/website/blob/gh-pages/CONTRIBUTING.md