Document SSL auto-enabled by extensions

[ppalaga]

Followup #1294 (comment)

We should decide how detailed we should document the fact that some extensions auto-enable SSL in native mode by producing a ExtensionSslNativeSupportBuildItem. Should we do this on extension pages? Should we have a list like in Quarkus https://github.com/quarkusio/quarkus/blob/master/docs/src/main/asciidoc/native-and-ssl.adoc ?

[ppalaga]

It is probably rather easy to add a generated text block on extension pages.

Something like

== SSL in native mode

This extension auto-enables SSL support in native mode. Hence you do not need to add
`quarkus.ssl.native=true` to your `application.properties` yourself. See also
https://quarkus.io/guides/native-and-ssl[Quarkus SSL guide].