Autosizing textarea

A variation of the textarea component that resizes as you type.
This is using the Autosize libarary.
Using this component will make each textarea component autogrow by default.
This component relies on the Textarea component.
Possible assumption
This component assumes that there is no other component that has a function with this name: compony_theme_suggestions_textarea_alter
.
If your theme already has this exact function name in use, you should copy the contents of this function and put them in the already existing one. (every function name in php has to be unique).
Specifications
Machine name
form-item--textarea--autosize
Built upon
Drupal Core
Building blocks
HTML
CSS
Javascript
Inspired by
Flat design