Feat: update Lighthouse plugin to use new MarkdownComponent (#3328)

plugins/lighthouse/package.json

@@ -34,7 +34,6 @@
     "@types/react": "^16.9",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
-    "react-markdown": "^4.3.1",
     "react-router-dom": "6.0.0-beta.0",
     "react-use": "^15.3.3"
   },

plugins/lighthouse/src/components/Intro/index.tsx

@@ -15,8 +15,7 @@
  */
 import React, { useState } from 'react';
 import { useLocalStorage } from 'react-use';
-import Markdown from 'react-markdown';
-import { ContentHeader, InfoCard } from '@backstage/core';
+import { ContentHeader, InfoCard, MarkdownContent } from '@backstage/core';
 import { makeStyles, Button, Grid, Tabs, Tab } from '@material-ui/core';
 import CloseIcon from '@material-ui/icons/Close';
 
@@ -116,8 +115,8 @@ function GettingStartedCard() {
         </>
       }
     >
-      {value === 0 && <Markdown source={USE_CASES} />}
-      {value === 1 && <Markdown source={SETUP} />}
+      {value === 0 && <MarkdownContent content={USE_CASES} />}
+      {value === 1 && <MarkdownContent content={SETUP} />}
     </InfoCard>
   );
 }