Specify how to get rid of cool down cycle

[friedger]

There are requests to improve stacking. Some discussions to place

• here PoX Cooldown Cycle stacks-network/stacks-core#4912
• and here https://forum.stacks.org/t/remove-cool-down-cycle-in-stacking/17899

This issue is to track the progress of the SIP related to changing the stacking process.

[friedger]

Draft available at #209

[friedger]

Currently, main discussion is happening on https://forum.stacks.org/t/remove-cool-down-cycle-in-stacking/17899/13

SIP draft is here: #211