Update README after repo transition

Signed-off-by: George Melikov <mail@gmelikov.ru>

Author: gmelikov

README.MD

@@ -1 +1,10 @@
-Docker image with fresh libabigail.
+Fresh libabigail for consistent and reproducible results.
+
+### Usage example:
+```
+# Main usage, run command inside pwd dir
+sudo docker run -it --rm -v $(pwd):/source ghcr.io/openzfs/libabigail YOUR_COMMAND
+
+# Example for OpenZFS
+sudo docker run -it --rm -v $(pwd):/source ghcr.io/openzfs/libabigail make checkabi
+```