[Feature Request] Add reading direction to the OPDS feed

[foux]

Describe your suggested feature

There exists readingProgression in the default context of Readium Web Publication Manifest. It would be great to add it to Komga OPDS feed, so that readers can retrieve reading direction set in Komga

Other details

No response

Acknowledgements

• [X] I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.
• [X] I have written a short but informative title.
• [X] I have updated the app to the latest version.
• [X] I will fill out all of the requested information in this form.

[gotson]

It's implemented in the new opds 2 feed, it will be available in the next release.