Update 10 files

- /docs/assignments/week04.md
- /docs/assignments/week05.md
- /docs/assignments/week06.md
- /docs/assignments/week07.md
- /docs/assignments/week08.md
- /docs/assignments/week09.md
- /docs/assignments/week10.md
- /docs/assignments/week11.md
- /docs/assignments/week12.md
- /docs/assignments/week13.md