Edit

add

Add a file to the git index (aka staging area)

param	type [= default]	description
fs [deprecated]	FSModule	The filesystem containing the git repo. Overrides the fs provided by the plugin system.
dir, gitdir	string, string	The working tree directory path, and optionally the git directory path
filepath	string	The path to the file to add to the index
return	Promise<void>	Resolves successfully once the git index has been updated

await new Promise((resolve, reject) => fs.writeFile(
  '$input((README.md))',
  `$textarea((# TEST))`,
  (err) => err ? reject(err) : resolve()
))
await git.add({ dir: '$input((.))', filepath: '$input((README.md))' })
console.log('done')