fix: [M3-8748] - Markdown cheatsheet link in Support ticket interface…

… has an expired domain (#11101)

* Update docs link to valid domain

* Added changeset: Link to expired Markdown cheatsheet domain

* Switch to a better docs link

packages/manager/.changeset/pr-11101-fixed-1729011064940.md

@@ -0,0 +1,5 @@
+---
+"@linode/manager": Fixed
+---
+
+Link to expired Markdown cheatsheet domain ([#11101](https://github.com/linode/manager/pull/11101))

packages/manager/src/features/Support/SupportTicketDetail/TabbedReply/MarkdownReference.tsx

@@ -1,10 +1,11 @@
-import { Theme } from '@mui/material/styles';
-import { makeStyles } from 'tss-react/mui';
 import * as React from 'react';
+import { makeStyles } from 'tss-react/mui';
 
 import { Link } from 'src/components/Link';
 import { Typography } from 'src/components/Typography';
 
+import type { Theme } from '@mui/material/styles';
+
 const useStyles = makeStyles()((theme: Theme) => ({
   example: {
     backgroundColor: theme.name === 'dark' ? theme.bg.white : theme.bg.offWhite,
@@ -30,7 +31,7 @@ export const MarkdownReference = (props: Props) => {
       <Typography>
         You can use Markdown to format your{' '}
         {props.isReply ? 'reply' : 'question'}. For more examples see this{' '}
-        <Link external to="http://demo.showdownjs.com/">
+        <Link external to="https://commonmark.org/help/">
           Markdown cheatsheet
         </Link>
       </Typography>