* Update mDNS and LEDC
* update toolchain
* Update IDF to 1c3dd23
* Advertise the board variant for Arduino OTA
* Add generic variant definition for mDNS
IDF Options:
- Autostart Arduino (implements app_main)
- Disable HAL locks
- Set HAL debug level
- Auto-connect STA if configured (else will connect after WiFi.begin())