Add an error component

Shows when a rendering error has been triggered, like the one in 5edc402a01

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/graphql/config.ts

@@ -112,6 +112,15 @@ export const ABOUT = gql`
   }
 `;
 
+export const CONTACT = gql`
+  query Contact {
+    config {
+      name
+      contact
+    }
+  }
+`;
+
 export const RULES = gql`
   query Rules {
     config {