possible values for the "cold" column

[tabascoeye]

What would you like to be added:
Documentation for the "cold" column which is shown in the "drives" table.

Why is this needed:
To understand, what is meant here

Additional context:
screenshot:

Difference between "empty" and "-" is unclear

(feeld free to insta-close this issue if I'm just too dumb to find the explanation)

[Dulanic]

It is basically when the usable range is lower than the expected range. This commonly happens when it's cold outside. The difference between - and blank is null vs false... the null ones happen because the usable battery level was null which can happen for various reasons. I'll put in a PR so null and false show as the same.