Add GitHub App Connections section to Platform Hub docs (#3125)

* Add GitHub App Connections section to Platform Hub docs

Documents how to configure a GitHub App Connection in Platform Hub and use it to set up version control, including limitations around template step usage.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Update src/pages/docs/platform-hub/index.md

Co-authored-by: Ryan Hall <ryan.hall@octopus.com>

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Ryan Hall <ryan.hall@octopus.com>

Author: 3 people

public/docs/i/1000/platform-hub/platform-hub-github-connections.webp

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+{"width":1637,"height":719,"updated":"2026-05-01T00:35:49.394Z"}