Fix : email.hbs docs url changed

Signed-off-by: Yun Min Woo <[email protected]>

src/mail/templates/email.hbs

@@ -240,7 +240,7 @@ table, td { color: #000000; } #u_body a { color: #0000ee; text-decoration: under
  Slack is an app used for collaboration. You can communicate with your team, as well as create and use channels as a community or for various purposes. In addition, you can connect Slack and GitHub, so you can receive notifications such as GitHub Puliquet and Issue.
  Sonar Cloud is a tool that easily integrates into the cloud DevOps platform and uses code review tools that extend CI/CD workflows when teams want to deliver clean code consistently and efficiently.
  VS Code extensions let you add languages, debuggers, and tools to your installation to support your development workflow.
- To learn more about these things or how to use them, visit this <a href="https://docs.open-set-go.com/docs/help/reference/" title="Reference documents">Reference documents</a>!
+ To learn more about these things or how to use them, visit this <a href="https://docs.open-set-go.com/docs/guideforclient/recommandation/community/" title="Reference documents">Reference documents</a>!
   <br /><br />If you want more information, you can refer to <a href="https://docs.open-set-go.com/" title="QnA">this github.io</a>. Also, if you have any questions that can't be solved, please feel free to ask through <a href="https://github.com/AgainIoT/Open-Set-Go/discussions/categories/q-a" title="QnA">the QnA page</a>!</span></p>
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