MyPy plugin to warn for component unpacking operators

[rmorshea]

Current Situation

Currently we don't document that using the unpacking operator (*args) has undesirable consequences on whether we do or don't warn about missing keys.

Proposed Actions

Document this fact. If it turns out that, despite this documentation, people run into this issue often, consider changing the syntax.

Work Items

• add docs on unpacking operator to "Rendering Data" docs.

[Archmonger]

@rmorshea Can I add a Todo (Docs) column to the GitHub Project's page to prevent documentation tasks from cluttering the task list?

It's hard to tell at first glance how much development actually needs to go into v1 since there's so many docs changes needed.

[rmorshea]

Go for it. Let me know if you're not able to.

[rmorshea]

I think a MyPy plugin could help with this

[Archmonger]

Changing this to issue a plugin, and moving to V2.