Merge branch 'main' into release

Week_2_1/PA/PA_2_1_classy_city.ipynb

Week_2_1/PA/PA_2_1_solution.ipynb

Week_2_1/PA/PA_dev.ipynb

Week_2_1/PA/README.md

Week_2_1/PA/U.ipynb

Week_2_1/PA/city copy.py

Week_2_1/PA/city.py

Week_2_1/PA/city_solution.py

Week_2_1/PA/dev.py

Week_2_1/PA/test.py

src/students/Week_2_1/PA_2_1_classy_city.html

src/students/Week_2_1/README.html