Update README.md

Author: richarddd

README.md

@@ -3,7 +3,22 @@
 This util allows for mapping any HttpServletRequest and HttpServletResponse to and from API gateway classes
 
 ## Installation
-TODO
+1. Add Jitpack to repos in gradle.build
+    
+    ```kotlin
+    repositories {
+       maven {
+           url = uri("https://jitpack.io")
+       }
+    }
+    ```
+
+2. Add dependency
+    ```kotlin
+    dependencies {
+        compile("com.github.richarddd:aws-lambda-api-gateway-servlet:master-SNAPSHOT")
+    }
+    ```
 
 ## Usage
 Example with javalin and aws lambda handler: