Add sources maven plugin

Author: juho05

pom.xml

@@ -56,6 +56,19 @@
             </execution>
           </executions>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-source-plugin</artifactId>
+          <version>3.2.1</version>
+          <executions>
+            <execution>
+              <id>attach-javadocs</id>
+              <goals>
+                <goal>jar</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
     </plugins>
     <pluginManagement>
       <plugins>