This option was removed in JRE 10 and its presence causes error on startup.
Artemis still does not compile on JDK 9 and up, so what I tried was
to compile on JDK 1.8 and then start Artemis on 1.8 and 10.
That now works for me.
This commit contains these changes:
* Change example documentation to use markdown
* Generate HTML doc based on markdown during release
* Fix XML formatting in some examples
* Repair out-of-date documentation