Fix possible inaccuracy in Lit_config_levels docstring

These are not necessarily what one means by the "scope" of a
configuration variable, in part because of the nature of the subtle
distinction between "user" and "global", and in part because of
other issues such as how setting a variable for a single command
with "-c" has a scope which is not listed.

This also brings the docstring somewhat more in line with how these
values are documented elsewhere in GitPython.

Author: EliahKagan

git/types.py

@@ -111,7 +111,7 @@
 Lit_config_levels = Literal["system", "global", "user", "repository"]
 """Type of literal strings naming git configuration levels.
 
-Such a string identifies what level, or scope, a git configuration variable is in.
+These strings relate to which file a git configuration variable is in.
 """
 
 ConfigLevels_Tup = Tuple[Literal["system"], Literal["user"], Literal["global"], Literal["repository"]]