Update README.md

Author: michael-ameri

README.md

@@ -1,2 +1,28 @@
-# gemini
-Java library for gemini api
+# Introduction
+Java library for Gemini API. 
+See the documentation here: https://ai.google.dev/gemini-api
+
+# Getting started
+- Generate an API key: https://aistudio.google.com/app/apikey
+
+# Usage
+## Dependency
+Add the `gemini-api` dependency. Maven example:
+
+        <dependency>
+            <groupId>swiss.ameri</groupId>
+            <artifactId>gemini-api</artifactId>
+            <version>${gemini.version}</version>
+        </dependency>
+
+## JsonParser
+In order for this library to stay free of dependencies, the user must provide an implementation of the `swiss.ameri.gemini.spi.JsonParser` class.
+Alternatively, an example gson implementation can be used with the following dependency (which includes a gson dependency)
+
+        <dependency>
+            <groupId>swiss.ameri</groupId>
+            <artifactId>gemini-gson</artifactId>
+            <version>${gemini.version}</version>
+        </dependency>
+
+# Versioning