Add comprehensive PostgreSQL and Redis documentation with examples

[amanluthra001]

What's Changed

• Added comprehensive PostgreSQL documentation with connection examples
• Added Redis documentation with caching examples
• Included code snippets, setup instructions, and best practices for both databases

Files Added/Modified

• docs/datasources/postgresql/page.md - PostgreSQL documentation
• docs/datasources/redis/page.md - Redis documentation

Testing

• Documentation pages reviewed for accuracy
• Code examples verified for syntax
• Consistent with existing documentation style

Both files include practical examples and configuration details for developers.

[KanavCode]

Can I work on this Issue @amanluthra001 under hacktoberfest ? Please Assign me...