Add feature to have different breathing intervals

[SeaDve]

[sojusnik]

Ideally, we should have 5 adjustable parameters:

1. length of a complete breathing session
2. length of inhalation
3. length of breath hold after inhalation
4. length of exhalation
5. length of breath hold after exhalation

Those should be saveable into different breathing programs so that you can easily switch between different individually created presets.

[gevera]

Thiis. It would be great to save personal presets, like Butyeko Method, Wim Hof etc