* Added solution for Project Euler problem 72.
* Update type annotations and 0-padding of the directory name. Reference: #3256
* Rename sol1.py to sol2.py
* Added newline at the end of sol2.py
* Revert sol1.py
* Rename all Project Euler directories:
Reason:
The change was done to maintain consistency throughout the directory
and to keep all directories in sorted order.
Due to the above change, some config files had to be modified:
'problem_22` -> `problem_022`
* Update scripts to pad zeroes in PE directories