📝 docs: add Sanity image URL feature to README

The README now includes information about the Sanity image URL generation
feature which provides automatic image resizing capabilities through the
@sanity/image-url package.

Author: w3bdesign

README.md

@@ -73,6 +73,7 @@ Fourth version of my personal portfolio website with Next.js, Motion, Sanity.io
 - Reusable GenericForm component for easy form creation and management
 - Error handling with react-error-boundary for improved user experience and easier debugging
 - AI-friendly repository documentation with automated updates (Repomix with Github action workflow)
+- Sanity image URL generation with automatic resizing via `@sanity/image-url`.
 
 ### Design
 
@@ -162,4 +163,4 @@ Fourth version of my personal portfolio website with Next.js, Motion, Sanity.io
     - Easy identification of test setup, execution, and verification
   - Simplified test maintenance and debugging
   - Automated validation through custom ESLint rules
-  - Tests will fail if AAA pattern is not followed
+  - Tests will fail if AAA pattern is not followed