chore: Remove Spectrum references (#1366)

* fix: knowledgebase -> knowledge base

* chore: Remove links and mentions to Spectrum community

server/emails/components/Footer.js

@@ -1,7 +1,7 @@
 // @flow
 import * as React from "react";
 import { Table, TBody, TR, TD } from "oy-vey";
-import { twitterUrl, spectrumUrl } from "../../../shared/utils/routeHelpers";
+import { twitterUrl } from "../../../shared/utils/routeHelpers";
 import theme from "../../../shared/styles/theme";
 
 type Props = {
@@ -46,9 +46,6 @@ export default ({ unsubscribeUrl }: Props) => {
             <a href={twitterUrl()} style={externalLinkStyle}>
               Twitter
             </a>
-            <a href={spectrumUrl()} style={externalLinkStyle}>
-              Spectrum
-            </a>
           </TD>
         </TR>
         {unsubscribeUrl && (