Document generic_thermostat enhancements for PR #136298.

[esand]

Documentation changes for min_cycle_duration, max_cycle_duration, and cycle_cooldown. Also adjustments regarding min_cycle_duration and keep_alive (they can now co-exist).

Proposed change

These changes document the changes proposed in home-assistant/core#136298.

Type of change

• Spelling, grammar or other readability improvements (current branch).
• Adjusted missing or incorrect information in the current documentation (current branch).
• Added documentation for a new integration I'm adding to Home Assistant (next branch).
  • I've opened up a PR to add logos and icons in Brands repository.
• Added documentation for a new feature I'm adding to Home Assistant (next branch).
• Removed stale or deprecated documentation.

Additional information

• Link to parent pull request in the codebase: Enhance generic_thermostat with min/max run time and cooldown time home-assistant/core#136298
• Link to parent pull request in the Brands repository:
• This PR fixes or closes issue: fixes #

Checklist

• This PR uses the correct branch, based on one of the following:
  • I made a change to the existing documentation and used the current branch.
  • I made a change that is related to an upcoming version of Home Assistant and used the next branch.
• The documentation follows the Home Assistant documentation standards.

[esand]

Seriously GitHub?