fix(storybook-babelrc): add emotion babel preset

To get emotion css prop type to show in storybook, it is required to add the babel preset to
`.storybook/.config`. It does not appear to be necessary in `rollup.config.js` for `css` styles to
appear in storybook, but will leave it in case it's required for `site` to use these components

.storybook/.babelrc

@@ -1,3 +1,6 @@
 {
-  "presets": [["@dsmjs", {"targets": {"browser": true}, "browser": true, "react": true}]]
+  "presets": [
+    ["@dsmjs", {"targets": {"browser": true}, "browser": true, "react": true}],
+    "@emotion/babel-preset-css-prop"
+  ]
 }

rollup.config.js

@@ -12,7 +12,10 @@ export default {
     babel({
       babelrc: false,
       exclude: ['./node_modules/**'],
-      presets: [['@dsmjs', {targets: {browser: true}, react: true, modules: false}], '@emotion/babel-preset-css-prop'],
+      presets: [
+        ['@dsmjs', {targets: {browser: true}, react: true, modules: false}],
+        '@emotion/babel-preset-css-prop'
+      ],
       plugins: [['transform-react-remove-prop-types', {mode: 'wrap'}]]
     })
   ],