Update tools/manual_api_docs/blocks/let.md

Co-authored-by: Matthieu Riegler <kyro38@gmail.com>

Author: MeAkib

tools/manual_api_docs/blocks/let.md

@@ -2,6 +2,7 @@
 
 ## Syntax
 
+<!-- prettier-ignore -->
 ```angular-html
 @let name = user.name;
 @let data = data$ | async;