Previous commit 81ea35c726 in main for 7.0
should have been applied in 6.2.x first for 6.2.1.
This commit applies the changes in 6.2.x as intended,
effective as of 6.2.13.
Closes gh-33974
Since we now use asciidoctor-tabs instead of spring-asciidoctor-backends,
we no longer need the `role="primary"` and `role="secondary"` attributes
for tab groups.
Closes gh-33506
This commit extract spring-related links and recurring external links
into asciidoctor attributes to be used by the Antora toolchain.
It notably homogenizes links to:
- IETF RFCs
- Java Community Process JSRs
- the Java API Documentation (on the Java 17 version)
- Kotlin documentations (on the Kotlinlang.org version)
- the Spring Boot reference guide (on the `html` version)
This commit also reworks most link attributes to follow a
Project-Category-Misc syntax. For example, `spring-boot-docs` rather
than `docs-spring-boot`.
Finally, it makes an effort to clean up remainders from the previous
documentation toolchain, namely the `docs/asciidoc` folder and
`modules/ROOT/pages/attributes.adoc` file.
Closes gh-26864
Closes gh-31619
rstoyanchev
Juergen Hoeller
Tran Ngoc Nhan
Sam Brannen
kexin.an
Simon Baslé
Rob Winch