Separate revnumber from author list

Update the CSS to make the `revnumber` visually distinct from the list
of authors. Unfortunately removing '.' after the last author isn't
possible using a pure CSS solution so some additional javascript has
been also added.

Closes gh-52

Author: philwebb

src/main/css/asciidoctor.css

@@ -63,15 +63,22 @@
   display: none;
 }
 
-.doc #header .details span.author:after {
+.doc #header .details span.author:not(:last-of-type)::after {
   content: "\2022";
   font-weight: 400;
   margin: 0.4em;
   color: var(--asciidoctor-author-separator-color);
 }
 
-#header .details span.author:nth-last-child(2):after {
-  content: "";
+.doc #header .details span.last-author::after {
+  display: none;
+}
+
+.doc #header .details #revnumber {
+  flex-basis: 100%;
+  margin-top: 0.5rem;
+  text-transform: capitalize;
+  font-weight: 200;
 }
 
 /* Section setup */

src/main/js/site/author.js

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+
+(function () {
+  "use strict";
+
+  markLastAuthor();
+
+  function markLastAuthor() {
+    let candidate = document.getElementById("author");
+    let lastAuthorElement = candidate;
+    while (candidate) {
+      if (candidate.classList.contains("author")) {
+        lastAuthorElement = candidate;
+      }
+      candidate = candidate.nextElementSibling;
+    }
+    if (lastAuthorElement) {
+      lastAuthorElement.classList.add("last-author");
+    }
+  }
+})();

src/test/asciidoc/spring.adoc

@@ -1,6 +1,7 @@
 [[spring]]
 = Asciidoctor Spring Extensions Document
 Andy Wilkinson; Phillip Webb
+v1.23
 :description: Asciidoctor using Spring extensions
 :toc: left
 :toc-levels: 4