docs: Link to new Discord (#507)

* Link to new Discord

* Remove some Spectrum links

Author: nickserv

docs/contributing.md

@@ -31,8 +31,7 @@ a 👍. This helps maintainers prioritize what to work on.
 For questions related to using the library, please visit a support community
 instead of filing an issue on GitHub.
 
-- [Spectrum][spectrum]
-- [Reactiflux on Discord][reactiflux]
+- [Discord][discord]
 - [Stack Overflow][stackoverflow]
 
 <!--
@@ -51,8 +50,6 @@ Links:
 [package]: https://www.npmjs.com/package/react-testing-library
 [downloads-badge]: https://img.shields.io/npm/dm/react-testing-library.svg?style=flat-square
 [npmtrends]: http://www.npmtrends.com/react-testing-library
-[spectrum-badge]: https://withspectrum.github.io/badge/badge.svg
-[spectrum]: https://spectrum.chat/testing-library
 [license-badge]: https://img.shields.io/npm/l/react-testing-library.svg?style=flat-square
 [license]: https://github.com/testing-library/react-testing-library/blob/master/LICENSE
 [prs-badge]: https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square
@@ -75,7 +72,7 @@ Links:
 [bugs]: https://github.com/testing-library/react-testing-library/issues?q=is%3Aissue+is%3Aopen+label%3Abug+sort%3Acreated-desc
 [requests]: https://github.com/testing-library/react-testing-library/issues?q=is%3Aissue+sort%3Areactions-%2B1-desc+label%3Aenhancement+is%3Aopen
 [good-first-issue]: https://github.com/testing-library/react-testing-library/issues?utf8=✓&q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc+label%3A"good+first+issue"+
-[reactiflux]: https://www.reactiflux.com/
+[discord]: https://discord.gg/c6JN9fM
 [stackoverflow]: https://stackoverflow.com/questions/tagged/react-testing-library
 
 <!-- prettier-ignore-end -->

website/core/Footer.js

@@ -55,11 +55,8 @@ class Footer extends React.Component {
             <ExternalLink href="https://stackoverflow.com/questions/tagged/react-testing-library">
               Stack Overflow
             </ExternalLink>
-            <ExternalLink href="https://www.reactiflux.com/">
-              Reactiflux on Discord
-            </ExternalLink>
-            <ExternalLink href="https://spectrum.chat/testing-library">
-              Spectrum
+            <ExternalLink href="https://discord.gg/c6JN9fM">
+              Discord
             </ExternalLink>
           </div>
           <div>

website/pages/en/help.js

@@ -35,7 +35,7 @@ function Help(props) {
       title: 'Spectrum',
     },
     {
-      content: `Chat on [Discord](https://www.reactiflux.com/)`,
+      content: `Chat on [Discord](https://discord.gg/c6JN9fM)`,
       title: 'Discord',
     },
     {