The use-case seems like it would be quite useful and natural: I would like a label to apply if ALL of the changed files are of a few certain types. For example:

documentation:
  - all: ["**/*.md", "**/*.puml"]

This of course doesn't work as all files need to match both patterns which never happens. Another attempt:

documentation:
  - all: ["**/*.md"]
  - all: ["**/*.puml"]

This almost works but does not work if the change touches both md files and puml files.

AFAICT there is no way to represent what I'm trying to do, but it feels like a very natural and useful case to support.