* add method for requesting attention to the main window
* use another enum member for user attention type instead of nested `Option`s
(also, document the enum members now that they don't mirror `winit`)
* update the docstring
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
* add an example app for testing window attention requests
* Apply suggestions from code review
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
* remove `chrono` dependency and improve the attention example's readability
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Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>