feat: Add Storybook a11y addon (#1335)

Co-authored-by: Cole Bemis <[email protected]>

Author: smockle

.storybook/main.js

@@ -4,6 +4,7 @@ module.exports = {
     "../src/**/*.stories.@(js|jsx|ts|tsx)"
   ],
   "addons": [
+    "@storybook/addon-a11y",
     "@storybook/addon-links",
     "@storybook/addon-essentials"
   ]

package-lock.json

@@ -78,6 +78,7 @@
     "@github/prettier-config": "0.0.4",
     "@rollup/plugin-commonjs": "19.0.0",
     "@rollup/plugin-node-resolve": "13.0.0",
+    "@storybook/addon-a11y": "6.3.4",
     "@storybook/addon-actions": "^6.2.9",
     "@storybook/addon-essentials": "6.2.9",
     "@storybook/addon-links": "^6.2.9",