Update Growatt Server documentation for API token authentication

[johanzander]

Proposed change

Updates the Growatt Server integration documentation to reflect the new API token authentication method added in home-assistant/core#149783.

Changes

• Added documentation for API token authentication using the official Growatt V1 API
• Clarified that API token authentication is currently supported for MIN/TLX inverters
• Added step-by-step instructions for obtaining an API token
• Updated text to clarify that users can select from multiple plants if available
• Improved overall readability and structure

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: Adds token authentication and usage of official API for Growatt MIN/TLX inverters core#149783
• 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.

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[c0ffeeca7]

Thank you for contributing, @johanzander 👍

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[c0ffeeca7]

I'm drafting this PR, as changes are needed.

Please undraft it once the changes have been implemented and the PR is ready for review again.

[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[c0ffeeca7]

I don't see any changes in this PR.

[johanzander]

must be an error, these changes are already merged, ill close this one.