chore: how to implement a new crd version (#227)

* chore: how to implement a new crd version

Signed-off-by: Skye Gill <[email protected]>

* Add CONTRIBUTING.md with development section for FeatureFlagConfiguration crd versioning

Signed-off-by: Skye Gill <[email protected]>

Signed-off-by: Skye Gill <[email protected]>

Author: skyerus

CONTRIBUTING.md

@@ -0,0 +1,20 @@
+## Guidelines
+
+Welcome!
+
+There are a few things to consider before contributing to open-feature-operator.
+
+Firstly, there's [a code of conduct](https://github.com/open-feature/.github/blob/main/CODE_OF_CONDUCT.md).
+TLDR: be respectful.
+
+Any contributions are expected to include tests. These can be validated with `make test` or the automated github workflow will run them on PR creation.
+
+The go version in the `go.mod` is the currently supported version of go.
+
+Thanks! Issues and pull requests following these guidelines are welcome.
+
+## Development
+
+### FeatureFlagConfiguration custom resource definition versioning
+Custom resource definitions support multiple versions. The kubebuilder framework exposes a system to seamlessly convert between versions (using a "hub and spoke" model) maintaining backwards compatibility. It does this by injecting conversion webhooks that call our defined convert functions. The hub version of the `FeatureFlagConfiguration` custom resource definition (the version to which all other versions are converted) is `v1alpha1`.
+Follow [this tutorial](https://book.kubebuilder.io/multiversion-tutorial/conversion-concepts.html) to implement a new version of the custom resource definition.