Add a flag to only write on clean repos (no pending changes to commit)

[acabal33uab]

Automatically fixing all typos is unpractical when the following happens:

• typos makes many undesired changes due to false positives.
• and typos is run on a repo with already many (manual) changes with respect to the last commit.
  In this case, rolling back is time consuming.

So I suggest a flag which only writes when there is nothing left to commit (result of git diff --exit-code &> /dev/null can be checked)