message: Update WarningPanel examples for accordion
diff: import React from 'react';
  import { WarningPanel } from './WarningPanel';
  -import { Link, Button } from '@material-ui/core';
  +import { Button, Link, Typography } from '@material-ui/core';
  export default {
  title: 'Feedback/Warning Panel',
  @@ -25,11 +25,11 @@ export default {
  export const Default = () => (
  <WarningPanel
  - title="Example Warning Title"
  + title="Entity missing annotation"
  message={
  <>
  - This example entity is missing something. If this is unexpected, please
  - make sure you have set up everything correctly by following{' '}
  + This example entity is missing an annotation. If this is unexpected,
  + please make sure you have set up everything correctly by following{' '}
  <Link href="http://example.com">this guide</Link>.
  </>
  }
  @@ -37,9 +37,36 @@ export const Default = () => (
  );
  export const Children = () => (
  - <WarningPanel title="Example Warning Title">
  - <Button variant="outlined" color="primary">
  - Supports custom children - for example this button
  - </Button>
  + <WarningPanel title="Could not contact backend system">
  + <Typography>
  + Supports custom children - for example these text elements. This can be
  + used to hide/expose stack traces for warnings, like this example:
  + <br />
  + SyntaxError: Error transforming
  + /home/user/github/backstage/packages/core/src/components/WarningPanel/WarningPanel.stories.tsx:
  + Unexpected token (42:16) at unexpected
  + (/home/user/github/backstage/node_modules/sucrase/dist/parser/traverser/util.js:83:15)
  + at tsParseMaybeAssignWithJSX
  + (/home/user/github/backstage/node_modules/sucrase/dist/parser/plugins/typescript.js:1399:22)
  + at tsParseMaybeAssign
  + (/home/user/github/backstage/node_modules/sucrase/dist/parser/plugins/typescript.js:1373:12)
  + at parseMaybeAssign
  + (/home/user/github/backstage/node_modules/sucrase/dist/parser/traverser/expression.js:118:43)
  + at parseExprListItem
  + (/home/user/github/backstage/node_modules/sucrase/dist/parser/traverser/expression.js:969:5)
  + </Typography>
  + <Button variant="contained">Learn More</Button>
  </WarningPanel>
  );
  +
  +export const FullExample = () => (
  + <WarningPanel
  + title="Could not contact backend system"
  + message="The backend system failed to respond. It is possible the service is down; please try again in a few minutes."
  + >
  + HTTP 500 Bad Gateway response from
  + https://usefulservice.mycompany.com/api/entity?44433
  + </WarningPanel>
  +);
  +
  +export const TitleOnly = () => <WarningPanel title="Could not load data." />;
  