feat(docs): improve docs with examples (#31)

- Add overview image to improve understanding on how garm-operator
fits into garm landscape
- provide examples for better understanding on how to use / interact
with operator

---------

Co-authored-by: Mario Constanti <github@constanti.de>

README.md

@@ -26,6 +26,8 @@
 
 `garm-operator` is a [Kubernetes®](https://kubernetes.io) operator that manages the lifecycle of [garm](https://github.com/cloudbase/garm) objects by creating/updating/deleting corresponding objects in the Kubernetes cluster.
 
+![garm components overview](docs/assets/overview.png "Architecture Overview")
+
 ## 🔀 Versioning
 
 ### Garm Version
@@ -102,4 +104,4 @@ Please visit <https://www.mercedes-benz-techinnovation.com/en/imprint/> for info
 
 Notice: Before you use the program in productive use, please take all necessary precautions,
 e.g. testing and verifying the program with regard to your specific use.
-The program was tested solely for our own use cases, which might differ from yours.
+The program was tested solely for our own use cases, which might differ from yours.