* improve example gui. Add simple pages
* return old progress bar with example
* base progress with steps, there is bug with step? 1 ~= 1, small delta?
* polish progress, check float error case
* add callback on end of "to" function, value check
* start of green/red in progress
* add first version of rich progress bar
* make green bar darker
* rich bar fixes
* add delay, before filling in rich progress
* PR fixes
* remove dublicate of 'progress_rich'
