Add CORS header to well-known matrix endpoints.

docker/server/nginx.conf

@@ -40,11 +40,13 @@ http {
 
         location /.well-known/matrix/server {
           default_type application/json;
+          add_header "Access-Control-Allow-Origin" *;
           return 200 '{"m.server": "matrix.fizz.buzz:8448"}';
         }
 
         location /.well-known/matrix/client {
           default_type application/json;
+          add_header "Access-Control-Allow-Origin" *;
           return 200 '{"m.homeserver":{"base_url": "https://matrix.fizz.buzz"}}';
         }
     }