Update README.md

Author: Tob1as

examples/fpm-nginx-dhi/README.md

@@ -17,6 +17,7 @@ Notes:
 If you don't want to use it, make adjustments in the NGINX configuration file in "config" folder.  
 * **Important: To pull Images from DHI you must login with your docker account.** 
 * (Sourcecode from DH-Images can found here [https://github.com/docker-hardened-images](https://github.com/docker-hardened-images/catalog/tree/main/image).)
+* DHI Docs: https://docs.docker.com/dhi
 * DHI images (mostly) have no shell and no entrypoint.
 * Images build for AMD64 (x86_64) and ARM64 with Linux.