Change element.io links to matrix.to links (#614)

* Change element.io links to matrix.to links

Following to the discussion in codimd/server#496, this commit changes element.io links to matrix.to in the new react-client as well.

* Updated cypress test for new link

cypress/integration/link.spec.ts

@@ -148,8 +148,8 @@ describe('Links Intro', () => {
     })
 
     it('Matrix', () => {
-      cy.get('a[href="https://app.element.io/#/room/#hedgedoc:matrix.org"]')
-        .checkExternalLink('https://app.element.io/#/room/#hedgedoc:matrix.org')
+      cy.get('a[href="https://matrix.to/#/#hedgedoc:matrix.org"]')
+        .checkExternalLink('https://matrix.to/#/#hedgedoc:matrix.org')
     })
 
     it('Mastodon', () => {

src/components/editor/app-bar/help-button/links.tsx

@@ -29,7 +29,7 @@ export const Links: React.FC = () => {
               <TranslatedExternalLink
                 i18nKey='editor.help.contacts.meetUsOn'
                 i18nOption={{ service: 'Matrix' }}
-                href={links.chatElement}
+                href={links.chat}
                 icon='hashtag'
                 className='text-primary'
               />

src/components/error-boundary/error-boundary.tsx

@@ -38,7 +38,7 @@ export class ErrorBoundary extends Component {
             <p>Don't worry, this happens sometimes. If this is the first time you see this page then try reloading the app.</p>
             If you can reproduce this error, then we would be glad if you&#32;
             <ExternalLink text={'open an issue on github'} href={frontendVersion.issueTrackerUrl} className={'text-primary'}/>&#32;
-            or <ExternalLink text={'contact us on matrix.'} href={links.chatElement} className={'text-primary'}/>
+            or <ExternalLink text={'contact us on matrix.'} href={links.chat} className={'text-primary'}/>
             <Button onClick={() => this.refreshPage()} title={'Reload App'} className={'mt-4'}>
               <ForkAwesomeIcon icon={'refresh'}/>&nbsp;Reload App
             </Button>

src/components/landing-layout/footer/social-links.tsx

@@ -10,7 +10,7 @@ const SocialLink: React.FC = () => {
       <Trans i18nKey="landing.footer.followUs" components={[
         <ExternalLink href={links.githubOrg} icon='github' text="GitHub"/>,
         <ExternalLink href={links.community} icon='users' text="Discourse"/>,
-        <ExternalLink href={links.chatElement} icon="comment" text="Element"/>,
+        <ExternalLink href={links.chat} icon="comment" text="Matrix"/>,
         <ExternalLink href={links.mastodon} icon='mastodon' text="Mastodon"/>,
         <ExternalLink href={links.translate} icon="globe" text="POEditor"/>
       ]}/>

src/links.json

@@ -1,5 +1,5 @@
 {
-    "chatElement": "https://app.element.io/#/room/#hedgedoc:matrix.org",
+    "chat": "https://matrix.to/#/#hedgedoc:matrix.org",
     "community": "https://community.codimd.org",
     "faq": "https://community.codimd.org/t/frequently-asked-questions/190",
     "githubOrg": "https://github.com/codimd/",