HOWTO dev misc yarn_setup

HOWTO: Yarn package manager setup

The Yarn package manager is (and can be) used instead of npm for any JS bundles, starting from Rails 5.1+. Add the installation key, update the package list and get it from the added official repository:

$ curl -sL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
$ echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
$ sudo apt-get update && sudo apt-get install yarn

Verify the installation:

$ yarn -v