docs/autogen_shortcuts.py: support Python 3.8 In 64e72a955 (Restore shortcuts in documentation, define identifiers, 2023-01-08), some typing annotations were added to docs/autogen_shortcuts.py using the builtin container type 'list'. This feature is only available starting in Python 3.9 [1], but setup.cfg lists Python 3.8 as the earliest supported Python version. This leads to a failing documentation build in a Python 3.8 virtual environment. Fix this by using the capitalized name 'List' from the 'typing' module to keep Python 3.8 compatibility. [1] https://docs.python.org/3/whatsnew/3.9.html#type-hinting-generics-in-standard-collections