Improved consistency with previous episodes and intro course.

[dc2917]

This PR improves consistency of episode "Managing contributions to code" with the previous episodes in this course, as well as with the introductory course.

• Sentence pointing to location of recipe_with_history.zip has been removed since students should not be deleting their work half way through the course.
• Details related to configuring a remote repo have been removed since this is now done as part of setup (subject to PR #33), and remote repo is used in previous episode anyway.
• Note to sync their main branch has been removed, since the previous episode finishes on main branch.

[AdrianDAlessandro]

Looks good to me!

Yes, in the setup