add usage.md

Author: rohitdaryanani

README.md

@@ -117,24 +117,7 @@ try {
 
 <a name="usage"></a>
 # Usage
-
-- [Example Code](https://github.com/sendgrid/java-http-client/tree/master/examples)
-
-The example uses SendGrid, you can get your free account [here](https://sendgrid.com/free?source=java-http-client).
-
-First, update your environment with your [SENDGRID_API_KEY](https://app.sendgrid.com/settings/api_keys).
-
-```bash
-echo "export SENDGRID_API_KEY='YOUR_API_KEY'" > sendgrid.env
-echo "sendgrid.env" >> .gitignore
-source ./sendgrid.env
-```
-
-```bash
-mvn package
-cd examples
-javac -classpath {path_to}/sendgrid-java-http-client-4.0.0-jar.jar:. Example.java && java -classpath {path_to}/sendgrid-java-http-client-4.0.0-jar.jar:. Example
-```
+[Library Usage Documentation](USAGE.md)
 
 <a name="roadmap"></a>
 # Roadmap

USAGE.md

@@ -0,0 +1,19 @@
+# Usage
+
+- [Example Code](https://github.com/sendgrid/java-http-client/tree/master/examples)
+
+The example uses SendGrid, you can get your free account [here](https://sendgrid.com/free?source=java-http-client).
+
+First, update your environment with your [SENDGRID_API_KEY](https://app.sendgrid.com/settings/api_keys).
+
+```bash
+echo "export SENDGRID_API_KEY='YOUR_API_KEY'" > sendgrid.env
+echo "sendgrid.env" >> .gitignore
+source ./sendgrid.env
+```
+
+```bash
+mvn package
+cd examples
+javac -classpath {path_to}/sendgrid-java-http-client-4.0.0-jar.jar:. Example.java && java -classpath {path_to}/sendgrid-java-http-client-4.0.0-jar.jar:. Example
+```