* Upgrade to Python 3.8 syntax

* updating DIRECTORY.md
Co-authored-by: Ngithub-actions <${GITHUB_ACTOR}@users.noreply.github.com>

* 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