use git to track transformed files

[milahu]

i have a similar script to remove typescript types, and generate pretty javascript
https://github.com/milahu/random/blob/master/javascript/tsx2jsx.mjs

that script will run 2 loops

1. rename files from *.ts to *.js
2. transform all files from step 1

inspect the transform: git diff HEAD^
revert the transform: git reset --hard HEAD~2

this could be hidden behind a flag like ts-to-jsdoc --git

[futurGH]

Like I mentioned on #10, I want to avoid expanding the surface area of this project without compelling reasoning & support for a feature from a number of users.