litepub schema: add oauthRegistrationEndpoint [ci skip]

priv/static/schemas/litepub-0.1.jsonld

@@ -19,7 +19,11 @@
             "value": "schema:value",
             "sensitive": "as:sensitive",
             "litepub": "http://litepub.social/ns#",
-            "directMessage": "litepub:directMessage"
+            "directMessage": "litepub:directMessage",
+            "oauthRegistrationEndpoint": {
+                "@id": "litepub:oauthRegistrationEndpoint",
+                "@type": "@id"
+            }
         }
     ]
 }