diff: add 'diff.wordDiff' config option
The git-diff(1) command supports the `--word-diff` which allows the users to specify how to delimit word diffs. Provide this option also as a config param 'diff.wordDiff'.
The git-diff(1) command supports the `--word-diff` which allows the users to specify how to delimit word diffs. Provide this option also as a config param 'diff.wordDiff'.