2023.3: Update KNX change description

[farmio]

Proposed change

to emphasize Data Secure support. The keyfile uploader is a requirement to use that. KNX users will probably know the term "Data Secure" 😀 . Its used to send Telegrams with end-to-end encrypted payloads. Afaic Home Assistant is now the first open platform supporting this 😁

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: Upload KNX Keyfile from Config/Options Flow directly core#88097
• 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.

[home-assistant]

It seems that this PR is targeted against an incorrect branch since it has a parent PR on one of our codebases. Documentation that needs to be updated for an upcoming release should target the next branch. Please change the target branch of this PR to next and rebase if needed.

[frenck]

Thanks, @farmio 👍

../Frenck