Add an [all] project.optional-dependencies

[vferat]

Add an all project.optional-dependencies to install dev + doc + test at once:

Should work by adding the section to pyproject.toml

all = [
  'CHANGEME[dev]',
  'CHANGEME[doc]',
  'CHANGEME[test]',
]

[effigies]

That would be fine. Slightly shorter to do CHANGEME[dev,doc,test].