exercise timers as immutable state machines on Typescript
fsm README.md - core logic
adapters README.md - stateful OO adapters for OO lib users
react README.md - react hook(s)
TODO keywords: immutable/functional, (optionally) deterministic, 0 dependency, timer with time concern separated/abstracted away
TODO reference implementations: react-native, mermaid
TODO reference-metronome
TODO publish properly (when NX really supports it) - or move to pnpm workspaces, publish from there
TODO round end warning time setting https://www.reddit.com/r/amateur_boxing/comments/16f4s7a/theres_a_lot_of_boxing_timer_apps_out_there_is/
TODO warmup time setting
TODO keep-awake - check it closes on stopped; add "exit" button
TODO drum inputs for react-native - Picker 
TODO skip break
TODO allow to stop from running stage
TODO settings storage