docs: setup envtest

Author: csviri

README.md

@@ -7,4 +7,10 @@ Project is in early phases, heading towards mvp release.
 
 ## Usage 
 
+### Download binaries
 
+[`setup-envtest`](https://pkg.go.dev/sigs.k8s.io/controller-runtime/tools/setup-envtest#section-readme) can be used
+to download binaries.
+
+by executing `setup-envtest use --bin-dir ~/.jenvtest` will download the latest binaries required to the default 
+directory.