markdown/asciidoc literate style should support running via .java not just .jshell

[maxandersen]

trafficstars

Is your feature request related to a problem? Please describe. some thing just don't work that well with jshell style code and would need a main method - like JavaFX examples to fully function.

Consider doing a main method check and treat it is .java with a main if found.

Should explore if it actually helps :)