remove slack links

The cncf slack channels will no longer be used.
Also touch up the page to mention Matrix and Discord first.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Author: Luap99

docusaurus.config.js

@@ -125,6 +125,10 @@ const config = {
           {
             title: 'Community',
             items: [
+              {
+                label: 'Matrix',
+                href: 'https://matrix.to/#/#podman:fedoraproject.org',
+              },
               {
                 label: 'Discord',
                 href: 'https://discord.com/invite/x5GzFF6QH4',

static/data/community.ts

@@ -2,7 +2,7 @@ import { MEETING_URL } from './global';
 const header = {
   title: 'Community',
   subtitle:
-    'We want your feedback, issues, patches, and involvement in the development of Podman. **Chat** with us on Slack, IRC, or on our **mailing list**. Submit **issues & pull requests** (see our [CONTRIBUTING guide](https://github.com/containers/podman/blob/main/CONTRIBUTING.md) on how.) Participate in one of our twice-monthly community meetings. You are welcome in our community!',
+    'We want your feedback, issues, patches, and involvement in the development of Podman. **Chat** with us on Matrix, Discord, IRC, or on our **mailing list**. Submit **issues & pull requests** (see our [CONTRIBUTING guide](https://github.com/containers/podman/blob/main/CONTRIBUTING.md) on how.) Participate in one of our twice-monthly community meetings. You are welcome in our community!',
   image: 'images/raw/podman-2-196w-172h.png',
   banner: {
     text: 'To help ensure all feel welcome in the Podman community, we expect all who participate to adhere to our [Code of Conduct](https://github.com/containers/common/blob/main/CODE-OF-CONDUCT.md)',
@@ -41,11 +41,6 @@ const communityChat = {
       path: 'https://discord.gg/vwpj7K6gW5',
       icon: 'logos:discord-icon',
     },
-    {
-      text: 'Slack',
-      path: 'https://cloud-native.slack.com/archives/C08MXJLCFCN',
-      icon: 'logos:slack-icon',
-    },
   ],
 };