JSP help: document age=x.x means “encoded in x.x”

[markusicu]

For the Age property, [:Age=6.0:] includes all characters that were encoded in 6.0 (or by 6.0), that is, characters whose Age property is at most 6.0. This is documented at https://www.unicode.org/reports/tr18/#Age but not obvious to the casual user.

Asmus asks that we document this on the utilities help page.

Plus: “At the same time, that page could be slimmed down by removing the list of available properties in favor of the page linked under "properties" from the top of the tool's page. If the lists are different, then an explicit listing of only the difference would be more useful.”