'__version__' is not defined in class AddonData

[zjosua]

The file addon/init.py does not import __version__.
I would've made a PR, but I'm not quite sure where the add-on's _version.py is supposed to be.
I'm guessing it should still (like in existing add-ons that use another (older?) version of libaddon) be src/module_name/_version.py, and libaddon/_version.py contains the version of libaddon?

  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/__init__.py", line 40, in startup
    from . import main
  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/main.py", line 28, in <module>
    from .gui.pokemanki_options import invoke_pokemanki_options
  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/gui/pokemanki_options.py", line 50, in <module>
    from ..libaddon.gui.content.about import getAboutString
  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/libaddon/gui/content/about.py", line 37, in <module>
    from ...addon import ADDON
  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/libaddon/addon/__init__.py", line 42, in <module>
    class AddonData(NamedTuple):
  File "/home/zjosua/.local/share/Anki2/addons21/pokemanki/libaddon/addon/__init__.py", line 49, in AddonData
    VERSION = __version__
NameError: name '__version__' is not defined