Storybook: Add a11y addon (#36790)

* Storybook: Add a11y addon

* Update lockfile

* Bump Storybook addon versions

* Put Icon at top

* addon-knobs 6.3.0

packages/grafana-ui/.storybook/main.ts

@@ -18,6 +18,7 @@ module.exports = {
         backgrounds: false,
       },
     },
+    '@storybook/addon-a11y',
     '@storybook/addon-knobs',
     '@storybook/addon-storysource',
     'storybook-dark-mode',

packages/grafana-ui/package.json

@@ -79,11 +79,12 @@
     "@rollup/plugin-commonjs": "16.0.0",
     "@rollup/plugin-image": "2.0.5",
     "@rollup/plugin-node-resolve": "10.0.0",
-    "@storybook/addon-essentials": "6.3.0",
+    "@storybook/addon-a11y": "6.3.5",
+    "@storybook/addon-essentials": "6.3.5",
     "@storybook/addon-knobs": "6.3.0",
-    "@storybook/addon-storysource": "6.3.0",
-    "@storybook/react": "6.3.0",
-    "@storybook/theming": "6.3.0",
+    "@storybook/addon-storysource": "6.3.5",
+    "@storybook/react": "6.3.5",
+    "@storybook/theming": "6.3.5",
     "@testing-library/jest-dom": "5.11.9",
     "@types/classnames": "2.2.7",
     "@types/common-tags": "^1.8.0",

packages/grafana-ui/src/components/Icon/Icon.story.tsx

@@ -7,7 +7,7 @@ import { useTheme } from '../../themes';
 import mdx from './Icon.mdx';
 
 export default {
-  title: 'General/Icon',
+  title: 'Docs overview/Icon',
   component: Icon,
   decorators: [withCenteredStory],
   parameters: {