Document embedded profiles of plugin-web-app

[ikalinin1]

ACs:

1. Defined list of supported profiles with description.
2. Documented properties allowing to set arguments, binary path and experimental options
3. Mobile emulation has a description of how to define a custom device, and where to find a list of supported by browser devices

https://docs.vividus.dev/vividus/latest/plugins/plugin-web-app.html#_profiles