docs: add GitHub Container Registry image usage instructions

Author: Finb

README.md

@@ -16,6 +16,12 @@ The docker image is already available, you can use the following command to run
 docker run -dt --name bark -p 8080:8080 -v `pwd`/bark-data:/data finab/bark-server
 ```
 
+You can also use the GitHub Container Registry image:
+
+``` sh
+docker run -dt --name bark -p 8080:8080 -v `pwd`/bark-data:/data ghcr.io/finb/bark-server
+```
+
 If you use the docker-compose tool, you can copy docker-copose.yaml under this project to any directory and run it:
 
 ``` sh