Fix directive format

Co-authored-by: Rene Brandel <[email protected]>

Author: palpatim

src/pages/gen1/[platform]/build-a-backend/graphqlapi/customize-authorization-rules/index.mdx

@@ -910,7 +910,7 @@ type PostTags
 }
 ```
 
-For more control over the join table's authorization rules, you can create the join table explicitly, linking it to each model with a `hasMany/belongsTo` relationship, and set appropriate auth rules for your application.
+For more control over the join table's authorization rules, you can create the join table explicitly, linking it to each model with a `@hasMany`/`@belongsTo` relationship, and set appropriate auth rules for your application.
 
 ### How it works