How to add Google Fonts to Drupal 8 theme, the PROPER way

YOURTHEMENAME.info.yml
libraries:
- 'YOURTHEMENAME/fonts'
YOURTHEMENAME.libraries.yml
fonts:
css:
theme:
'//fonts.googleapis.com/css?family=Roboto+Condensed:300italic,400,300,700|Open+Sans:300italic,400,300': { type: external, minified: true }