Migrate geo_json_events platform to integration with config flow

[exxamalte]

Proposed change

Adapted documentation to reflect proposed changes of the integration to config flow. Removed YAML based configuration examples. Made small enhancements to the existing documentation to align with other similar 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: https://github.com/home-assistant/core/pull/70439
• Link to parent pull request in the Brands repository:
• This PR fixes or closes issue: fixes #

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.

[exxamalte]

Just rebased to latest next branch; no changes to content.

[exxamalte]

I reduced the scope of the parent PR in the codebase to only migrate to config flow, so the latest change in the documentation reflects that.