Module 2 sorting algs activity

[vkxu657]

Final part of Module 2 edits. Edited Activity 2 in Module 3 (meant for Module 2) called Sorting.

Issues Closed

Please make one new line for each issue, otherwise not all issues will be accounted for!

Closes #949

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Changes proposed in this pull request: *Bullet Point Summary

• Final part of edits for Module 2 content
• Edited all of Activity 2 called "Sorting" in Module 3 (but meant for Module 2) @reviewer/kavuong