Update documentation for new ZHA config entry flow

[Adminiuga]

Proposed change

Update documentation for new config flow for ZHA integration.

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: New configuration flow for ZHA integration core#35161
• 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.

[Adminiuga]

This is ready to go in, as the change was already merged.

[frenck]

Yes, we know @Adminiuga...

The label parent-merged is set and will be picked up when processing those.

[frenck]

👍 LGTM ✅