improved documentation

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