Add contribution doc

docs/contribution.md

@@ -0,0 +1,30 @@
+# Contribution
+
+Thanks for taking the time to contribute to metabase-operator.
+
+## How to make PR
+
+You can create a PR into `main` when your feature is ready. We will review it within 2 days.
+
+## Local development with minikube
+
+1. To try a new feature, first create a minikube cluster.
+```bash
+minikube start
+```
+2. Clone this repository.
+```bash
+git clone git@github.com:unagex/metabase-operator.git
+cd metabase-operator
+```
+3. Make your changes in the code.
+4. Run the binary against the minikube cluster with the following command. There is no need to build the docker image.
+```bash
+make install run
+```
+You should see the following log:
+![image](./local-dev.png)
+5. The operator is now running on minikube, you can create the custom resource and see how the operator handles it.
+```bash
+kubectl apply -f config/samples/v1_metabase.yaml
+```