feat(server): send mention email (#10859)

close CLOUD-170

packages/backend/server/src/mails/index.tsx

@@ -1,5 +1,6 @@
 import { render as rawRender } from '@react-email/components';
 
+import { Mention } from './docs';
 import {
   TeamBecomeAdmin,
   TeamBecomeCollaborator,
@@ -114,6 +115,13 @@ export const Renderers = {
   ),
   //#endregion
 
+  //#region Doc
+  Mention: make(
+    Mention,
+    props => `${props.user.email} mentioned you in ${props.doc.title}`
+  ),
+  //#endregion
+
   //#region Team
   TeamWorkspaceUpgraded: make(TeamWorkspaceUpgraded, props =>
     props.isOwner