Marking npm module as deprecated in favour of Prettier's --check option

[kachkaev]

Hi @pomber and @n1ru4l! 👋 Thanks for your work on this package – I've been using it in all my projects for over a year after seeing prettier-check one day in Apollo Server's package.json. A few weeks ago, I decided to add the --check to Prettier's CLI and this new flag eventually became a part of version 1.16 (see their blog post).

It is now possible to replace prettier-check with prettier --check in package.json scripts section and then run yarn remove prettier-check. All will work as before, but there'll be fewer dependencies to install (see prettier/prettier#5520 for some stats).

WDYT of deprecating this package to encourage people to switch to the --check flag? You can do this with the following command:

npm deprecate prettier-check 'Use "prettier --check" instead of "prettier-check" (available since Prettier 1.16)'

The repo's description or README.md can also get a similar message at the top.

Many thanks for your work again! Your module really helped a lot of teams to get their code formatting done right! 🙌 👍