Update directory.owncast.online -> owncast.directory (#4485)

* chore: change directory.owncast.online -> owncast.directory. For #4483

* chore: update extracted translations

---------

Co-authored-by: Owncast default web localizations <owncast@owncast.online>

web/i18n/en/translation.json

@@ -2,7 +2,7 @@
   "Add your Owncast instance to the Fediverse": "Add your Owncast instance to the Fediverse",
   "Admin": {
     "EditInstanceDetails": {
-      "directoryDescription": "Increase your audience by appearing in the <a href=\"https://directory.owncast.online\" target=\"_blank\" rel=\"noreferrer\"><strong>Owncast Directory</strong></a>. This is an external service run by the Owncast project. <a href=\"https://owncast.online/docs/directory/?source=admin\" target=\"_blank\" rel=\"noopener noreferrer\">Learn more</a>.",
+      "directoryDescription": "Increase your audience by appearing in the <a href=\"https://owncast.directory\" target=\"_blank\" rel=\"noreferrer\"><strong>Owncast Directory</strong></a>. This is an external service run by the Owncast project. <a href=\"https://owncast.online/docs/directory/?source=admin\" target=\"_blank\" rel=\"noopener noreferrer\">Learn more</a>.",
       "offlineMessageDescription": "The offline message is displayed to your page visitors when you're not streaming. Markdown is supported.",
       "serverUrlRequiredForDirectory": "You must set your <strong>Server URL</strong> above to enable the directory."
     },