Adds a clean-generated target to remove stale generated files (#4082)

* Adds a clean-generated target to remove stale generated files

* Update the docs for make generate

Author: carmal891

Makefile

@@ -60,9 +60,15 @@ CEL_TEST_CRD_CHANNEL ?= standard
 
 all: generate vet fmt verify test
 
+.PHONY: clean-generated
+clean-generated:
+	rm -rf pkg/client/clientset
+	rm -rf pkg/client/listers
+	rm -rf pkg/client/informers
+
 # Run generators for protos, Deepcopy funcs, CRDs, and docs.
 .PHONY: generate
-generate: update-codegen
+generate: clean-generated update-codegen
 
 .PHONY: update-codegen
 update-codegen:

site-src/contributing/devguide.md

@@ -61,7 +61,7 @@ outside $GOPATH as well.
 
 ### Build the Code
 
-The project uses `make` to drive the build. `make` will run code generators, and
+The project uses `make` to drive the build. `make` will clean up previously generated code, run code generators, and
 run static analysis against the code and generate Kubernetes CRDs. You can kick
 off an overall build from the top-level makefile: