Nicegui

- provide optional socket in `page.on_disconnect`
- replaced "interactive mode" with simpler solution (see 71 and 74)

Changes

- re-organized, simplified and improved examples
- removed `ui.svg` because its just `ui.html`

Bugfixes

- update page after a websocket connected (in case it missed a ui update)
- update parent element when adding element to main page (without entering/exiting a context)
- use page from parent view instead from page stack to solve (70)
- fixed font when running behind reverse proxy with prefixed path (64)
- other minor fixes

- docker image now based on python 3.10
- minor documentation fixes

- introducing `on_page_ready` callback for ui.page
- bugfies
- made sure our own print statements are shown
- fixed rendered texture side
- added missing ui update for markdown
- cleaner DOM for `ui.notify`

- introduction of `scene.text` and `scene.text3d` to render text in 3d
- fixed timer update behaviour