Added explain for developing. (#160)

How to compile etc..

CONTRIBUTE.md

@@ -0,0 +1,94 @@
+# For developers
+
+## Compile
+
+To compile, just run the make command. (default is jdk8)
+
+```
+make
+```
+
+If you want to change the version of the jdk, just pass the VERSION argument to the make command.
+The following is an example of compiling with jdk7.
+
+```
+make VERSION=7
+```
+
+Note: If you are compiling for jdk6, please check the java6_support branch.
+
+## Test
+
+```
+make test
+```
+
+## More
+
+If you want to use the `mvn` command directly, you can register what you are doing in Makefile to Bash's function as follows and do what you want.
+
+```bash
+wovnjava-mvn () {
+  docker run -it --rm -v ${PWD}:/project -v wovnjava-maven_repo:/root/.m2 -w /project maven:3-jdk-8 mvn $@
+}
+
+
+wovnjava-mvn build -f pom.xml
+
+wovnjava-mvn test -f pom.xml
+```
+
+## How to use it in docker
+
+If you want to use a locally compiled version of wovnjava, please use the following method.
+
+Remove or comment out the repository configuration in jitpack.io and enable the dependency systemPath instead.
+
+docker/java8/hello/pom.xml:
+
+```
+  <repositories>
+    <repository>
+      <id>jitpack.io</id>
+      <url>https://jitpack.io</url>
+      <snapshots>
+        <enabled>true</enabled>
+        <updatePolicy>always</updatePolicy>
+      </snapshots>
+      <!-- end -->
+    </repository>
+  </repositories>
+```
+
+Make sure you have the correct version number enabled in dependency.
+
+docker/java8/hello/pom.xml:
+
+```
+  <dependencies>
+      <dependency>
+          <groupId>com.github.wovnio</groupId>
+          <artifactId>wovnjava</artifactId>
+          <version>1.4.0</version>
+          <!-- If you use local compiled version. -->
+          <scope>system</scope>
+          <systemPath>${basedir}/lib/wovnjava-1.4.0-jar-with-dependencies.jar</systemPath>
+      </dependency>
+  </dependencies>
+```
+
+Copy the locally compiled wovnjava to the lib directory of the Hello project.
+Compile the Hello project together with wovnjava.
+
+```
+mkdir -p docker/java8/hello/src/main/webapp/WEB-INF/lib/
+cp target/wovnjava-1.4.0-jar-with-dependencies.jar docker/java8/hello/src/main/webapp/WEB-INF/lib/
+
+cd docker/java8
+./maven-clean-package.sh
+```
+
+For more information on how to use the docker environment, please refer to the following
+
+[docker/README.md](docker/README.md)
+