* Add a new `timg_timer1` symbol to `esp-metadata` definitions
* Make `Timer::load_value` fallible (when the value is too large)
* Clean up, simplify, and document the `timer` module and its submodules
* Fix various issues
* Update the timeout value verification for `SYSTIMER`
* Clippy
* Introduce new `PERIOD_MASK` constant for validating timeout values