Added configs for Ghost's ActivityPub integration

[therobbiedavis]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description

Added the locations required by Ghost to use their ActivityPub integration. See: https://docs.ghost.org/update-major-version#get-activitypub-ready

Benefits of this PR and context

This is a new feature of Ghost v6. It adds a "Network" tab in the Ghost admin section, that previously would just error out. This allows for usage of this feature by default as intended by the Ghost developers.

How Has This Been Tested?

I added this on a subdomain (does not work on a subfolder config) and checked the "Network" tab in the Ghost admin page to verify it was working and not erroring out.

Source / References

https://docs.ghost.org/update-major-version#get-activitypub-ready
https://docs.ghost.org/install/docker#enabling-social-web-activitypub
https://github.com/TryGhost/Ghost-CLI/blob/main/extensions/nginx/templates/nginx.conf#L13-L31
https://forum.ghost.org/t/upgrade-from-5-to-6-using-portainer/59226/5

[LinuxServer-CI]

This pull request has been automatically marked as stale because it has not had recent activity. This might be due to missing feedback from OP. It will be closed if no further activity occurs. Thank you for your contributions.

[therobbiedavis]

Any comments @drizuid, @aptalca, or others?