Add width/height: 100% styles in Storybook preview (#1834)

Author: rogermparent

webview/.storybook/preview.ts

@@ -1,6 +1,7 @@
 import { InternalVsCodeApi } from '../src/shared/api'
 import { action } from '@storybook/addon-actions'
 import { viewports } from '../src/stories/util'
+import './styles.scss'
 
 declare global {
   interface Window {

webview/.storybook/styles.scss

@@ -0,0 +1,4 @@
+#root {
+  width: 100%;
+  height: 100%;
+}