openapi2crd: initial commit (#2692)

* initial commit

* rename module

Author: s-urbaniak

tools/openapi2crd/Makefile

@@ -0,0 +1,7 @@
+.PHONY: generate
+generate:
+	hack/generate.sh
+
+.PHONY: crds
+crds:
+	go run main.go --config config.yaml --output crds.yaml

tools/openapi2crd/README.md

@@ -0,0 +1,14 @@
+## Running
+
+Example:
+```shell
+$ go run main.go \
+  --config config.yaml \
+  --output crds.yaml
+```
+## Acknowledgements
+
+The work is inspired by:
+- https://github.com/fybrik/openapi2crd
+- https://github.com/ant31/crd-validation
+- https://github.com/kubeflow/crd-validation.