Add "y" shortcut for permalink

Author: jsha

static/menu.js

@@ -235,4 +235,17 @@
         menu.firstElementChild.addEventListener("click", menuOnClick);
     }
     document.documentElement.addEventListener("keydown", menuKeyDown);
+    document.documentElement.addEventListener("keydown", function(ev) {
+        if (ev.key == "y") {
+            let permalink = document.getElementById("permalink");
+            if (document.location.hash != "") {
+              permalink.href += "#" + document.location.hash;
+            }
+            // Note: It would be nicer to do history.replaceState here and avoid a page load
+            // (that's what GitHub does), but the permalink goes through a redirect, so you wind up
+            // with a weird URL like:
+            // http://localhost:3000/crate/regex/1.3.1/target-redirect/x86_64-unknown-linux-gnu/regex/index.html
+            permalink.click();
+        }
+    });
 })();

templates/rustdoc/topbar.html

@@ -24,7 +24,7 @@
 
                     {%- if metadata.version_or_latest == "latest" -%}
                     <li class="pure-menu-item">
-                        <a href="{{permalink_path | safe}}" class="pure-menu-link description" title="Get a link to this specific version">
+                        <a href="{{permalink_path | safe}}" class="pure-menu-link description" id="permalink" title="Get a link to this specific version">
                             {{ "link" | fas }} Permalink
                         </a>
                     </li>