chore(storybook): rename deprecated files, update addon configuration.

Author: ElijahKotyluk

packages/@vuetify/storybook/generator/template/_storybook/main.js

@@ -0,0 +1,11 @@
+module.exports = {
+  stories: ['./stories/**/*.stories.js'],
+  addons: [
+    '@storybook/addon-knobs/register',
+    '@storybook/addon-actions/register',
+    '@storybook/addon-viewport/register',
+    '@storybook/addon-a11y/register',
+    '@storybook/addon-docs/register',
+    './addon-show-vue-markup/register',
+  ],
+}