message: docs(button-group): added stable-selectors and props tables
  ### Changelog
  **New**
  Stable selectors table;
  Props table.
diff: import { Preview, Props, Description, Story } from '@storybook/addon-docs/blocks';
  import contributing from '../../../../../../docs/contributing-license.md';
  -import ExpressiveModal from './ExpressiveModal';
  +import '../button-group';
  +import '../button-group-item';
  # Button Group
  @@ -41,4 +42,21 @@ import 'carbon-web-components/es/icons/arrow--right/20.js';
  </dds-button-group>
  ```
  +## Props
  +
  +<Props of="dds-button-group" />
  +
  +### `<dds-button-group-item>`
  +
  +<Props of="dds-button-group-item" />
  +
  +## Stable selectors
  +
  +See [our README](https://github.com/carbon-design-system/carbon-for-ibm-dotcom/tree/master/packages/web-components#stable-selectors-for-analytics-and-integratione2e-testing-in-web-components) to see how Web Components selector and `data-autoid` should be used.
  +
  +| Web Components selector | Compatibility selector | Description |
  +| ------------------------- | -------------------------------------- | ----------- |
  +| `<dds-button-group>` | `data-autoid="dds--button-group"` | Component |
  +| `<dds-button-group-item>` | `data-autoid="dds--button-group-item"` | Component |
  +
  <Description markdown={contributing} />
  