Now forums can enroll their sites to be showcased in the Discourse [Discover](https://discourse.org/discover) directory. Once they enable the site setting `include_in_discourse_discover` to enroll their forum the `CallDiscourseHub` job will ping the `api.discourse.org/api/discover/enroll` endpoint. Then the Discourse Hub will fetch the basic details from the forum and add it to the review queue. If the site is approved then the forum details will be displayed in the `/discover` page.
This is useful in the DiscourseHub mobile app, currently the app queries
the `about.json` endpoint, which can raise a CORS issue in some cases,
for example when the site only accepts logins from an external provider.
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
The opensearch.xml results in a "site search engine" being added to
Chrome, while the sitelinks search tag results in "Search this website"
being added to Google Search.
