Moving Learn Git further into workflow

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Based on a comment about the overall workflow, I think it makes sense to move Learn Git down farther in the workflow. This change makes it better match our group organization as well. (You don't need to know Git to set up your projects, milestones, issues, etc.)

• Link to the merge request that introduced the new page: gitlab!144114 (comment 1879564902)
• Give the MR a descriptive title.

Before:

After: