add README

Author: simingweng

client-java-contrib/prometheus-operator/README.md

@@ -0,0 +1,28 @@
+# Cert-Manager Model Classes
+This module contains the Java model classes generated from the release version of [prometheus operator](https://github.com/prometheus-operator/prometheus-operator) CRDs.
+
+It makes it possible to CRUD custom resources defined by `prometheus operator` in a strong-typed manner in your Java application, such as create a prometheus instance, write a prometheus rule, etc.
+## Usage
+To use this library, include the following maven dependency
+```xml
+<dependency>
+    <groupId>io.kubernetes</groupId>
+    <artifactId>client-java-prometheus-operator-models</artifactId>
+    <version>0.38.1-SNAPSHOT</version>
+</dependency>
+```
+Please refer to the [PromOpExample](../../examples/src/main/java/io/kubernetes/client/examples/PromOpExample.java), which demonstrates how to create a minimal prometheus instance with the model class and Kubernetes Java client generic API.
+## Compatibility
+Artifact Version|Cert-Manager Release Version|CRD Source
+----------------|----------------------------|----------
+0.38.1-SNAPSHOT|0.38.1|[Here](https://github.com/prometheus-operator/prometheus-operator/tree/master/example/prometheus-operator-crd)
+## Code Generation
+There is a utility script [update.sh](update.sh) to help with the code generation.
+
+* The only prerequisites required is Docker installed on the host
+
+Under the `prometheus-operator` directory, execute:
+```shell script
+./update.sh
+```
+It will generate the model classes from the CRDs hosted at the URL specified via the `-u` options in the [update.sh](update.sh) script. If newer version of CRDs becomes available, just update the `-u` options accordingly.