docs: local development

Author: vknabel

README.md

@@ -6,6 +6,19 @@
 
 ## Getting Started
 
+### Local Development
+
+```bash
+make -C capi-lab
+eval $(make -C capi-lab --silent dev-env)
+kubectl apply -f ../firewall-controller-manager/config/crds
+kubectl create -f https://github.com/prometheus-operator/prometheus-operator/releases/download/v0.77.1/bundle.yaml
+clusterctl init
+make push-to-capi-lab
+
+kubectl apply -k config/samples
+```
+
 ### Prerequisites
 - go version v1.23.0+
 - docker version 17.03+.