Add warning to notify users how to fix missing device in options flow

[RobBie1221]

Proposed change

Add a warning how to fix when a device is missing from the device list in the options flow.

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 logo's 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: Filter rfxtrx configure devices option flow on existing config entry core#40975
• Link to parent pull request in the Brands repository:
• This PR fixes or closes issue:

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.

[RobBie1221]

Parent has actually been merged. Better late than never...
I think it's in place to put a warning in the docs how users can fix it when a device is missing from the device list in the options flow instead of asking them to find the core PR to see the notes there.

[frenck]

Thanks, @RobBie1221 👍