v3.3 dark mode with printing mode

Darkmode [2021-04-19-2021-07-23]

• style: up
• process images macros smaller & light/dark & dark/light for images
• Set light theme for code
• Add printing mode (required after dark mode)
• [prototype] init of darkmode

Add:

• 2021-02-23 Add ADD_EXTRA_SPACE_FOR_NOTES for printed notes for extra space for pdfs for Boox
• 2021-02-22 TOC now handles h4 and h5 level headers
• 2021-02-14 insert_image.py: handle file://localhost/localhost/private
• 2021-02-11/23 Add to engine/process_md.py: ways to do quick actions with from the editor via ![#rm]()
  - #rm
  - #open
  - #fork
  - #min
• 2021-02-08 page: export file (with images) with --add-toc --push --readme

Change:

• 2021-02-11 engine/plugins/insert_image.py: works also on /

Fix:

• 2021-01-26 insert_image.py: fix pngfiles:///
• 2021-01-26 insert_image.py: fix getting dates, a new function with ifs, add #
• 2021-01-05 fix: dont crash when there is space in name (but files are simply skipped)