Migrate to MkDocs - Githubissues

See the website at honzajavorek.github.io/mkdocs-python.cz. This is a proof of concept and a work in progress.

Goals

Give up on complicated custom solutions which have little added value, but enormous overhead
Give up on custom design, because there is nobody in the community to maintain custom designs
Use as much existing software as possible
Make the website easy to maintain, easy to edit, easy to contribute

Intentionally not trying to achieve feature parity with existing python.cz website.

[x] port static content
[x] customize the theme
[x] events as a plugin
[x] fix absolute links and make them relative
[x] icons (index is here: https://emojipedia.org/twitter)
[x] images
[x] legacy redirects
[x] analytics
[x] english version
[x] delete the old code
[ ] use https://github.com/juniorguru/teemup to get events from meetup.com
[ ] keep tests which make sense and delete the rest
[ ] better readme
[ ] triage https://github.com/pyvec/python.cz/issues and close all irrelevant issues
[ ] update https://docs.pyvec.org/guides/calendar.html and link it from the site
[ ] create issue (nice to have): social cards - https://squidfunk.github.io/mkdocs-material/setup/setting-up-social-cards/
[ ] create issue (nice to have): logo should be on a white circle
[ ] create issue (nice to have) for each of the TODOs in the page content