Add make help command

[msherif1234]

Signed-off-by: Mohamed Mahmoud mmahmoud@redhat.com

make help
test                            Run tests
test-e2e                        Run e2e tests
manager                         Build manager binary
run                             Run against the configured cluster
install                         Install CRDs into a cluster
uninstall                       Uninstall CRDs from a cluster
deploy                          Deploy controller in the configured cluster
manifests                       Generate manifests e.g. CRD, RBAC etc.
fmt                             Run go fmt against code
vet                             Run go vet against code
generate                        Generate code
docker-build                    Build the docker image
docker-push                     Push the docker image
controller-gen                  Find or download controller-gen
generate-metallb-manifests      Generate metallb manifests
validate-metallb-manifests      Validate metallb manifests
help                            Show this help

If you are adding new make target just add a comment starts with ## beside the new target and describe what this command do, then confirm you can see the output with make help