Outdated Resource Links in README

[baharehforoughi]

I noticed that there are three outdated resource links at the end of the README file in the github-starter-course repository: 1- How to use GitHub branches 2-GitHub's Learning Lab 3-Education community forum Unfortunately, these resources are no longer available or have been moved.

[egrace479]

The third still exists, but the first two do give 404's.