contributing info

Author: hauner

CONTRIBUTING.md

@@ -0,0 +1,46 @@
+# contributing to openapi-generatr
+
+## feature & bug reports
+
+In case some feature is missing or the generated code is not 100% what you would expect please create
+an issue with test case. Providing a test case will help significantly :-) 
+
+A test case is a single folder with an openapi.yaml file and the expected Java files the generatr
+should create. The structure looks like this:
+
+    my-new-test-case/
+                     openapi.yaml
+                     mapping.yaml
+                     generated/
+                               api/
+                                  AnEndpointInterface.java
+                                  .. more api interfaces ..
+                               model/
+                                     AModelClass.java
+                                     AnotherModelClass.java
+                                     .. more model files ..
+
+The `mapping.yaml` contains the type mapping information and is an optional file.
+
+See the [existing integration tests][generatr-int-resources] for a couple of examples.
+
+## working on the code
+
+### jdk
+
+the minimum jdk is currently JDK 8
+
+### ide setup
+
+openapi-generatr can be imported into IntelliJ IDEA by opening the `build.gradle` file.
+ 
+### running the tests
+
+To run the tests use `./gradlew check`. 
+
+`check` runs the unit tests and the integration tests  
+
+### documentation
+
+The documentation is in `docs`. See the `README` in `docs` for setup and viewing it locally.
+