Added usage to readme

README.md

@@ -4,6 +4,36 @@ Keep the Kubernetes `CustomResourceDefinitions` that you rely on day-to-day from
 
 This simple library and CLI application transforms a [`CustomResourceDefinition`](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) into a [JSON Schema](https://json-schema.org/) for easier editing.
 
+## Usage
+
+### As a standalone CLI application
+
+```bash
+$ npx crd2jsonschema crd.yaml > schema.json
+```
+
+### In your project
+
+Add `CRD2JsonSchema` to your JavaScript/Typescript application:
+
+```bash
+$ npm i crd2jsonschema
+```
+
+Call the converter within your project:
+
+```typescript
+...
+import convertCrd, { K8sCrd } from 'crd2jsonschema';
+
+// Load the file
+const file = fs.readFileSync('crd.yaml', 'utf-8');
+// For Typescript users, validate your CRDs against K8sCrd
+const crd = YAML.parse<K8sCrd>(file);
+
+const schema = convertCrd(crd);
+```
+
 ## How does it work?
 
 Kubernetes CRDs currently use [OpenAPIv3](https://swagger.io/specification/) to define [the shape of custom objects](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#create-a-customresourcedefinition).