Update content/docs/app-developer-guide/using-cache-image.md

Co-authored-by: Aidan Delaney <[email protected]>
Signed-off-by: Domenico Luciani <[email protected]>

Author: Domenico Luciani

content/docs/app-developer-guide/using-cache-image.md

@@ -85,7 +85,7 @@ pack build localhost:5000/buildpack-examples/second-cache-image-example \
 ```
 <!--+- "{{execute}}"+-->
 
-### Images retention
+### Image Retention
 
 Managing the lifecycle of images should be the responsibility of the owner, as `the platform does not automatically clean up old images from the registry`.   
 You can refer to your registry's documentation to learn how to accomplish this.