Redirect to EECS 485 GitHub tutorial

[awdeorio]

Remove GitLab tutorial and replace with a redirect to the EECS 485 Version Control Tutorial.

The EECS 485 version control tutorial is a copy of the former EECS 280 tutorial, updated from GitLab to GitHub.

Prerequisites

• [x] Merge EECS 485 PR https://github.com/eecs485staff/p1-insta485-static/pull/426 which adds a few changes for EECS 280 students, like downloading the EECS 280 .gitignore

Validation

• Verify that the redirect works by clicking on the Git tutorial from the preview main page
• Read through the EECS 485 tutorial (after PR above is merged) and looks for EECS 485 things that might confuse an EECS 280 student.

[github-actions[bot]]

The spec from this PR is available at https://preview.sesh.rs/previews/eecs280staff/tutorials/86/.

^{(Available until Sun Feb 12 2023.)}

[awdeorio]

Perhaps we could add a note in the 485 git tutorial for 280 students, mentioning things like "use a different name than p1-insta-static", etc.

Like this at the top? Or did you ahve something else in mind? "We're assuming that you already have a folder, e.g., p1-insta485-static/. Your folder name may be different. It's OK if there aren't any files in it yet."

[ohjuny]

I guess we could just add one more example with a 280 project, so like:

"We're assuming that you already have a folder, e.g., p1-insta485-static/ or p2-cv/. Your folder name may be different. It's OK if there aren't any files in it yet."

[awdeorio]

This is ready to go!