Add contribution documention

Fixes #296

spring-ai-docs/src/main/antora/modules/ROOT/nav.adoc

@@ -42,5 +42,6 @@
 ** xref:api/etl-pipeline.adoc[]
 ** xref:api/testing.adoc[]
 ** xref:api/generic-model.adoc[]
+* xref:contribution-guidelines.adoc[Contribution Guidelines]
 * Appendices
 ** xref:upgrade-notes.adoc[]]

spring-ai-docs/src/main/antora/modules/ROOT/pages/contribution-guidelines.adoc

@@ -0,0 +1,36 @@
+[[contribution-guidelines]]
+= Contribution Guidelines
+
+== Contributing a New AI Model Implementation
+
+This section outlines the steps for contributing a new AI model implementation.
+AI models vary significantly, with diverse inputs and outputs -- from chat models that
+translate text input into text output, to text-to-image models that generate images
+from text descriptions.
+Complex models may even handle multiple types of input and output, such as combining text,
+images, and videos to produce mixed media output.
+
+To contribute a new model, adhere to the following steps:
+
+. *Create a Low-Level Client API Class*: If no existing Java client suits the AI model,
+you'll need to develop a low-level client API class. This often involves utilizing the
+`RestClient` class from the Spring Framework, similar to the `OpenAiApi` class.
+
+. *Create a ModelClient implementation*
+Ensure your client conforms to the link:https://docs.spring.io/spring-ai/reference/api/clients/generic-model.html[Generic Model API].
+Use existing request and response classes if your model's inputs and outputs are supported.
+If not, create new classes for the Generic Model API and establish a new Java package.
+
+. *Implement Auto-Configuration and a Spring Boot Starter*: This step involves creating the
+necessary auto-configuration and Spring Boot Starter to easily instantiate the new model with
+Spring Boot applications.
+
+. *Write Tests*: All new classes should be accompanied by comprehensive tests.
+Existing tests can serve as a useful reference for structuring and implementing your tests.
+
+. *Document Your Contribution*: Ensure your documentation follows the existing format,
+For an example of the suggested structure and formatting, refer to the
+link:https://docs.spring.io/spring-ai/reference/api/clients/openai-chat.html[Open AI Chat documentation].
+
+By following these guidelines, we can greatly expand the framework's range of supported models
+while following a common implementation and documentation pattern.