[SUREFIRE-2162] Document upcoming mojo and file names change

This closes #628

maven-surefire-report-plugin/src/site/apt/index.apt

@@ -58,6 +58,24 @@ Maven Surefire Report Plugin
 | 3.0.0                                       | {{{https://issues.apache.org/jira/issues/?jql=project%20%3D%20SUREFIRE%20AND%20fixVersion%20%3D%203.0%20ORDER%20BY%20priority%20DESC%2C%20key}ASF Release versions}}         \ |
 *---------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 
+* Upcoming Incompatibility Notice
+
+  With a future minor version several mojos and output filenames will change for alignment with other
+  reporting plugins from <<<org.apache.maven.plugins>>>.
+  To make you aware of that, see the following table for the upcoming changes:
+
+*----------------------*--------------------------*-----------------------*------------------*
+|| Mojo Class Name     || New Mojo Class Name     || Output name          || New Output Name |
+*----------------------+--------------------------+-----------------------+------------------+
+| <<<FailsafeReport>>> | <<<FailsafeReportOnly>>> | <<<failsafe-report>>> | <<<failsafe>>>   |
+*----------------------+--------------------------+-----------------------+------------------+
+| <<<SurefireReport>>> | \u2013                   | <<<suresafe-report>>> | <<<surefire>>>   |
+*----------------------+--------------------------+-----------------------+------------------+
+| <<<SurefireReportOnly>>> | \u2013               | <<<suresafe-report>>> | <<<surefire>>>   |
+*----------------------+--------------------------+-----------------------+------------------+
+
+  Details about this change can be found in {{{https://issues.apache.org/jira/browse/SUREFIRE-2161}SUREFIRE-2161}}.
+
 * Goals Overview
 
   The Surefire Report Plugin has three goals: