Update modbus configuration to use new

[janiversen]

Proposed change

Update documentation to reflect the new modbus configuration.

Moved the platform pages into the modbus (integration) page, since this is a list of integrations.

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.
• [ x] 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:

home-assistant/core#46591

• Link to parent pull request in the Brands repository:
• This PR fixes or closes issue:

Checklist

• [x ] 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.
• [ x] The documentation follows the Home Assistant documentation standards.

[frenck]

Is this related to a parent PR?

[janiversen]

yes #46591 I wrote that above but did not make a link, sorry for that. I have updated the text

[janiversen]

Update to reflect documentation error, that was already merged in current.

[frenck]

Thanks, @janiversen 👍