Update README

Explained the two different modules and how to run the examples

README.md

@@ -1,3 +1,30 @@
+# OpenAI-Java
+Java libraries for using OpenAI's GPT-3 api.
+
+Includes the following artifacts:
+- api : request/response POJOs for the GPT-3 engine, completion, and search APIs.
+- client : a basic retrofit client for the GPT-3 endpoints
+
+as well as an example project using the client.
+
+## How to use this
+If you're looking for the fastest solution, import the `client` and use [OpenAiService](openai-client/src/main/java/openai/OpenAiService.java).
+```
+OpenAiService service = new OpenAiService(your_token)
+CompletionRequest completionRequest = new CompletionRequest();
+completionRequest.setPrompt("Somebody once told me the world is gonna roll me");
+completionRequest.setEcho(true);
+service.createCompletion("ada", completionRequest).getChoices().forEach(System.out::println);
+```
+
+If you're using retrofit, you can import the `client` module and use the [OpenAiApi](openai-client/src/main/java/openai/OpenAiApi.java).  
+You'll have to add your auth token as a header (see [AuthenticationInterceptor](openai-client/src/main/java/openai/AuthenticationInterceptor.java))
+and set your converter factory to use snake case and only include non-null fields.
+
+If you want to make your own client, just import the POJOs from the `api` module.
+
+## Running the example project
+All the [example](example/src/main/java/example/OpenAiApiExample.java) project requires is your OpenAI api token
 ```
 export OPENAI_TOKEN="sk-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
 ./gradlew example:run