fix: update web learning API

fix: mkdir when there is no docs or work ...

fix #59

fix: strip homework title

fix: sort files by upload time

fix: fail to download answer attachment

fix: use Typer app instead of command

fix: migrate to typer

fix: compatible with py3.10

fix: fix usage as module

fix: migrate to python 3.11

fix: auto skip submit & comment attachment

style: format

feat: refactor