📃 Add readme example

Author: bdsoha

README.md

@@ -6,7 +6,16 @@
 
 ## Documentation
 
-TBD
+### Example
+
+```sh
+docker run --rm \
+  -v ./playbooks:/workspace \
+  ghcr.io/kloudkit/ansible-controller \
+  --inventory /workspace/hosts.yaml \
+  -e FOO=bar \
+  /workspace/play.yaml
+```
 
 ## License