Beginner-friendly Github instructions

[njhenry]

It would be nice to have very beginner-friendly Github instructions on our page showing the whole process of editing the CUGOS site:

1. Forking the site
2. Cloning locally—either with Git CLI or the Github desktop app
3. Making changes, committing pushing
4. Pull requesting back to this repo

This could be either a detailed step-by-step written guide, or a video tutorial. Steps 2 and 3 can happen various ways depending on your computer setup, and it would be nice if the tutorial could show (the easiest version of) multiple workflows.

Our Github Wiki does some of this, but it would be nice to have a more detailed instructions. At the very least, the images on the tutorial need to be fixed.

[mizmay]

I'd suggest deleting the Wiki and starting fresh, since both pages there have not been maintained in a long time, and may not be maintained again. A short section in the main page / README.md, or a separate .md file, or a page on the website, would be more central to operations and therefore easier to maintain.