Michelle 4/1

[mxthu313]

Jose Closes #616 Closes #619 Closes #925

Changes proposed in this pull request:

• Finished making leetcode activity
• worked on context

Allie Closes #503 Closes #622 Closes #922 Closes #923 Closes #927 Closes #928 Closes #929 Closes #932 Closes #933 ...

Changes proposed in this pull request:

• doubly linked list big o analysis
• zoologist (bubble, insertion, selection sort) big o analysis

Emily Closes #620 Closes #623 Closes #924 Closes #926 Closes #930 Closes #931 Closes #934 ...

Changes proposed in this pull request:

• added concepts from airtable
• edited cards to requested changes
• added visual and explanations
• fixed typos

@kavuong