added note on maven version

Author: chrjohn

.mvn/wrapper/maven-wrapper.properties

@@ -14,5 +14,7 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
+#
+# NOTE: maven version should also be changed in pom.xml
 distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.8/apache-maven-3.9.8-bin.zip
 wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.3.2/maven-wrapper-3.3.2.jar