chore: add resource under postgresql-dba:rdbms-concepts:object-model:data-types

src/data/roadmaps/postgresql-dba/content/102-rdbms-concepts/100-object-model/105-data-types.md

@@ -57,4 +57,6 @@ PostgreSQL provides special data types to work with geometric and network data:
 - **`point`, `line`, `lseg`, `box`, `polygon`, `path`, `circle`**: Geometric data types to store points, lines, and various shapes.
 - **`inet`, `cidr`**: Network data types to store IP addresses and subnets.
 
-In summary, PostgreSQL offers a broad range of data types that cater to different types of information. Understanding these data types and how to use them effectively will help you design efficient database schemas and optimize your database performance.
+In summary, PostgreSQL offers a broad range of data types that cater to different types of information. Understanding these data types and how to use them effectively will help you design efficient database schemas and optimize your database performance.
+
+- [An introduction to PostgreSQL data types](https://www.prisma.io/dataguide/postgresql/introduction-to-data-types)