docs: add social media links to website footer and README

Add links to Superset's social media presence (X, LinkedIn, Bluesky, Slack)
in the Docusaurus website footer with brand-colored SVG icons, and in the
README's "Get Involved" section.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -185,6 +185,10 @@ Try out Superset's [quickstart](https://superset.apache.org/docs/quickstart/) gu
 - [Join our community's Slack](http://bit.ly/join-superset-slack)
   and please read our [Slack Community Guidelines](https://github.com/apache/superset/blob/master/CODE_OF_CONDUCT.md#slack-community-guidelines)
 - [Join our dev@superset.apache.org Mailing list](https://lists.apache.org/list.html?dev@superset.apache.org). To join, simply send an email to [dev-subscribe@superset.apache.org](mailto:dev-subscribe@superset.apache.org)
+- Follow us on social media:
+  [X](https://x.com/apachesuperset) |
+  [LinkedIn](https://www.linkedin.com/company/apache-superset) |
+  [Bluesky](https://bsky.app/profile/apachesuperset.bsky.social)
 - If you want to help troubleshoot GitHub Issues involving the numerous database drivers that Superset supports, please consider adding your name and the databases you have access to on the [Superset Database Familiarity Rolodex](https://docs.google.com/spreadsheets/d/1U1qxiLvOX0kBTUGME1AHHi6Ywel6ECF8xk_Qy-V9R8c/edit#gid=0)
 - Join Superset's Town Hall and [Operational Model](https://preset.io/blog/the-superset-operational-model-wants-you/) recurring meetings. Meeting info is available on the [Superset Community Calendar](https://superset.apache.org/community)
 

docs/docusaurus.config.ts

@@ -634,6 +634,20 @@ const config: Config = {
     footer: {
       links: [],
       copyright: `
+          <div class="footer__social-links">
+            <a href="https://bit.ly/join-superset-slack" target="_blank" rel="noopener noreferrer" title="Join us on Slack" aria-label="Slack">
+              <img src="/img/community/slack-symbol.svg" alt="Slack" />
+            </a>
+            <a href="https://x.com/apachesuperset" target="_blank" rel="noopener noreferrer" title="Follow us on X" aria-label="X">
+              <img src="/img/community/x-symbol.svg" alt="X" />
+            </a>
+            <a href="https://www.linkedin.com/company/apache-superset" target="_blank" rel="noopener noreferrer" title="Follow us on LinkedIn" aria-label="LinkedIn">
+              <img src="/img/community/linkedin-symbol.svg" alt="LinkedIn" />
+            </a>
+            <a href="https://bsky.app/profile/apachesuperset.bsky.social" target="_blank" rel="noopener noreferrer" title="Follow us on Bluesky" aria-label="Bluesky">
+              <img src="/img/community/bluesky-symbol.svg" alt="Bluesky" />
+            </a>
+          </div>
           <div class="footer__ci-services">
             <span>CI powered by</span>
             <a href="https://www.netlify.com/" target="_blank" rel="nofollow noopener noreferrer"><img src="/img/netlify.png" alt="Netlify" title="Netlify - Deploy Previews" /></a>

docs/src/styles/main.css

@@ -218,10 +218,39 @@ a > span > svg {
 
 .footer {
   position: relative;
-  padding-top: 90px;
+  padding-top: 130px;
   font-size: 15px;
 }
 
+.footer__social-links {
+  background-color: #173036;
+  position: absolute;
+  top: 45px;
+  left: 0;
+  width: 100%;
+  padding: 10px 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 24px;
+}
+
+.footer__social-links a {
+  display: inline-flex;
+  align-items: center;
+  transition: opacity 0.2s, transform 0.2s;
+}
+
+.footer__social-links a:hover {
+  opacity: 0.8;
+  transform: scale(1.1);
+}
+
+.footer__social-links img {
+  height: 24px;
+  width: 24px;
+}
+
 .footer__ci-services {
   background-color: #0d3e49;
   color: #e1e1e1;
@@ -267,6 +296,21 @@ a > span > svg {
 }
 
 @media only screen and (max-width: 996px) {
+  .footer {
+    padding-top: 120px;
+  }
+
+  .footer__social-links {
+    top: 42px;
+    gap: 20px;
+    padding: 8px 16px;
+  }
+
+  .footer__social-links img {
+    height: 20px;
+    width: 20px;
+  }
+
   .footer__ci-services {
     gap: 12px;
     padding: 10px 16px;

docs/static/img/community/slack-symbol.svg

@@ -0,0 +1,21 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+-->
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="40" height="40" fill="#4A154B">
+  <path d="M5.042 15.165a2.528 2.528 0 0 1-2.52 2.523A2.528 2.528 0 0 1 0 15.165a2.527 2.527 0 0 1 2.522-2.52h2.52v2.52zm1.271 0a2.527 2.527 0 0 1 2.521-2.52 2.527 2.527 0 0 1 2.521 2.52v6.313A2.528 2.528 0 0 1 8.834 24a2.528 2.528 0 0 1-2.521-2.522v-6.313zM8.834 5.042a2.528 2.528 0 0 1-2.521-2.52A2.528 2.528 0 0 1 8.834 0a2.528 2.528 0 0 1 2.521 2.522v2.52H8.834zm0 1.271a2.528 2.528 0 0 1 2.521 2.521 2.528 2.528 0 0 1-2.521 2.521H2.522A2.528 2.528 0 0 1 0 8.834a2.528 2.528 0 0 1 2.522-2.521h6.312zm10.124 2.521a2.528 2.528 0 0 1 2.522-2.521A2.528 2.528 0 0 1 24 8.834a2.528 2.528 0 0 1-2.52 2.521h-2.522V8.834zm-1.271 0a2.528 2.528 0 0 1-2.521 2.521 2.528 2.528 0 0 1-2.521-2.521V2.522A2.528 2.528 0 0 1 15.166 0a2.528 2.528 0 0 1 2.521 2.522v6.312zm-2.521 10.124a2.528 2.528 0 0 1 2.521 2.522A2.528 2.528 0 0 1 15.166 24a2.528 2.528 0 0 1-2.521-2.52v-2.522h2.521zm0-1.271a2.528 2.528 0 0 1-2.521-2.521 2.528 2.528 0 0 1 2.521-2.521h6.312A2.528 2.528 0 0 1 24 15.165a2.528 2.528 0 0 1-2.52 2.521h-6.313z"/>
+</svg>