Add CORS header for Gitea OAuth

docker/docker/caddy/Caddyfile

@@ -46,6 +46,20 @@ pad.pbrinkmeier.de {
 }
 
 git.pbrinkmeier.de {
+    # Allow apps to requests tokens 'n stuff
+    @oauth path /login/oauth/*
+    header @oauth {
+        Access-Control-Allow-Origin "*"
+        Access-Control-Allow-Methods "GET, POST, OPTIONS"
+        Access-Control-Allow-Headers "Content-Type, Authorization"
+    }
+
+    @oauth_preflight {
+        path /login/oauth/*
+        method OPTIONS
+    }
+    respond @oauth_preflight 204
+
     reverse_proxy gitea:3000
 }