fix community link [404 not found] (facebook#30313)

Summary:
The README file in this repo has a bad link - [404:NotFound]

Status code [404:NotFound] - Link: https://reactnative.dev/en/help

## Changelog

fixed link: https://reactnative.dev/help

[Link] [fixed] - fixed broken link.

Pull Request resolved: facebook#30313

Test Plan: ![image](https://user-images.githubusercontent.com/46071874/98048666-5fe91c00-1e58-11eb-804e-b90f6d77b15f.png)

Reviewed By: yungsters

Differential Revision: D24716546

Pulled By: cpojer

fbshipit-source-id: 684285e5cc0bb6fadc88c1f25d77b38d482084ce

README.md

@@ -36,7 +36,7 @@
   <span> · </span>
   <a href="https://reactnative.dev/docs/contributing">Contribute</a>
   <span> · </span>
-  <a href="https://reactnative.dev/en/help">Community</a>
+  <a href="https://reactnative.dev/help">Community</a>
   <span> · </span>
   <a href="https://github.com/facebook/react-native/blob/master/.github/SUPPORT.md">Support</a>
 </h3>