Invalid GitHub Learning Lab link in git-guides/git-overview.md

[ivintoiu]

Summary

The link to GitHub Learning Lab in git-guides/git-overview.md points to an invalid domain. Clicking it returns NS_ERROR_UNKNOWN_HOST

Actual Behavior

[Introduction to GitHub Learning Lab course](https://lab.github.com/githubtraining/introduction-to-github) points to a non-existing domain

Expected Behavior

The link should direct to the correct location for the course.

Suggested

Update the URL to https://skills.github.com/, respectively https://github.com/skills/introduction-to-github

[malcolmjr96]

Here are some resources that are more specific to Git and GitHub.

Introduction to Git
Introduction to GitHub

That said, I feel like the authors suggestion is probably better since its GitHub directly, however, I couldn't find the url to the introduction to Git right away.