Dupal 8 Theme not under appearance

Hi all,
I am brand new to drupal. I am trying to get my theme listed in the appearance tab. My theme name is naked
folder structure: /themes/naked
yml file: /themes/naked/naked.info.yml

naked.info.yml contents:
name: naked
type: theme
description: 'Theme from scratch.'
base theme: classy
core: 8.x

I beleive this is all the basic info and format required per https://www.drupal.org/theme-guide/8/defining-a-theme

I am not sure why my theme that litterally is just a yml file is not working.... Thanks for the help.