Wrappers for esp-idf watchdog

[basvs]

(haven't checked whether the esp-idf has a watchdog..)

[Roosted7]

I think FreeRTOS has that exposed

[annejan]

It should, I remember seeing Watchdog warnings early in development.

[basvs]

https://esp-idf.readthedocs.io/en/latest/api-reference/system/wdts.html

Could use this to add these methods:

• esp32.wdt_init(ms) — ms is the max. number of milliseconds between two wdt_feed() calls.
• esp32.wdt_reset() ­— reset config; disable watchdog
• esp32.wdt_feed() — have to periodically call this method to avoid badge reboot.

Something like this?