Add GPM integration

[tomasbedrich]

Proposed change

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: Add GPM integration core#125144
• Link to parent pull request in the Brands repository: Add GPM brands#5884
• This PR fixes or closes issue: none

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.

Summary by CodeRabbit

• New Features
  • Introduced GIT Package Manager (GPM) integration for Home Assistant, enabling easy management of custom components and dashboard resources.
  • Users can install third-party integrations directly from public GIT repositories with a simple configuration flow.
  • Automated updates for components and dashboard resources, enhancing the user experience.
  • Lightweight alternative to existing solutions, offering a pure GIT approach without third-party dependencies.