Since 2.3.8 and 2.4.2, the documented index format does not match the implementation

[wilkinsona]

#24192 changed the index to include the directory name in its entries, e.g. dependency.jar became BOOT-INF/lib/dependency.jar. This allowed the entries in the index to match what the JarLauncher looks for when creating its classpath. The docs weren't updated at the same time so they're now out of sync with the implementation. Complicating things further, the Java buildpack looks for the old directory-less format so it has been broken by the change.

@ekcasey has kindly offered to fix the buildpack but I'd like to double-check that we don't want to try to align the implementation with the docs (and therefore with what the buildpack looks for) instead.

[wilkinsona]

We've decided to update the documentation.