ISR routine documentation

Notably absent in Arduino documentation is the listing of available ISR routines for a particular interrupt and microcontroller e.g. ISR(TIM0_OVF_vect) is the Timer 0 Overflow interrupt vector.
For each board officially supported by the Arduino IDE, a listing of each ISR with a brief description would be helpful.

Start by reviewing the Arduino Reference documentation and the ISR(TIM0_OVF_vect) example, then identify the supported boards and their interrupt vectors. Done means each officially supported board has a listing of its available ISR routines with a brief description, including the Timer 0 Overflow vector.

Written by the indexing model from the issue text.