document local mock setup for development (#45)

README.md

@@ -3,3 +3,29 @@
 [![CI Build](https://github.com/axonivy-market/deepl-connector/actions/workflows/ci.yml/badge.svg)](https://github.com/axonivy-market/deepl-connector/actions/workflows/ci.yml)
 
 Read our [documentation](deepl-connector-product/README.md).
+
+
+## Development
+
+To maintain this project and simulate requests there's no necessity to have a DeepL account and accessible environment.
+
+### Mocking
+Setup the mock service for DeepL requests, which provides static results. This mock is enabled when running JUnit tests, but it can be enabled for the normal Designer as follows:
+
+- Use your File Manager to navigate into the `configuration` directory of your Axon.ivy Designer.
+- Create a file called `app.yaml` and add the following contents with an editor:
+
+    ```yaml
+    # yaml-language-server: $schema=https://json-schema.axonivy.com/app/12.0.0/app.json
+    RestClients:
+    deepl:
+        Url: '{ivy.app.baseurl}/api/mock'
+        Properties:
+        AUTH.deepLKey: notMyKey
+        Features:
+        - ch.ivyteam.ivy.rest.client.mapper.JsonFeature
+        - org.glassfish.jersey.media.multipart.MultiPartFeature
+        - ch.ivyteam.ivy.rest.client.security.CsrfHeaderFeature
+    ```
+- Run any startable Process in the Demo project and verify in the RuntimeLog view, that requests are being sent to localhost rathern than deepl.com.
+