Set ?device={device} when changing tab in installation guides (vllm…

…-project#12560)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/source/_static/custom.js

@@ -1,3 +1,4 @@
+// Add RunLLM widget
 document.addEventListener("DOMContentLoaded", function () {
     var script = document.createElement("script");
     script.type = "module";
@@ -15,4 +16,23 @@ document.addEventListener("DOMContentLoaded", function () {
 
     script.async = true;
     document.head.appendChild(script);
-  });
+  });
+
+// Update URL search params when tab is clicked
+  document.addEventListener("DOMContentLoaded", function () {
+    const tabs = document.querySelectorAll(".sd-tab-label");
+
+    function updateURL(tab) {
+      const syncGroup = tab.getAttribute("data-sync-group");
+      const syncId = tab.getAttribute("data-sync-id");
+      if (syncGroup && syncId) {
+          const url = new URL(window.location);
+          url.searchParams.set(syncGroup, syncId);
+          window.history.replaceState(null, "", url);
+      }
+    }
+
+    tabs.forEach(tab => {
+        tab.addEventListener("click", () => updateURL(tab));
+    });
+});