Give user option to specify "mine"/"theirs" default resolution behavior

[farisj]

What's Up

Sometimes when comparing files and deciding between a current and an example value for a given key, users will want to set a rule to always choose the example value over the current, or vice versa.

Now, users are given a value by value CLI where they can decide what to keep. This is redundant if the users always know that they will want to select from .env.example and overwrite, for example.

Solution

Implement a flag/feature/customization to allow the user to specify a default "resolution" method when given differing current and example values.