feat: Subtitle typed animation

layout/_partial/after-footer.ejs

@@ -6,6 +6,20 @@
 <%- js('fancybox/jquery.fancybox.min') %>
 <% } %>
 
+<% if (theme.subtitle.enable){ %>
+<script src="https://cdn.jsdelivr.net/npm/typed.js@2.0.11/lib/typed.min.js"></script>
+<script>
+  var typed = new Typed("#subtitle", {
+    strings: ['<%= theme.subtitle.text %>'],
+    startDelay: <%= theme.subtitle.startDelay %>,
+    typeSpeed: <%= theme.subtitle.typeSpeed %>,
+    loop: <%= theme.subtitle.loop %>,
+    backSpeed: <%= theme.subtitle.backSpeed %>,
+    showCursor: <%= theme.subtitle.showCursor %>
+    });
+</script>
+<% } %>
+
 <% if (theme.toc && is_post()){ %>
 <%- js('/js/tocbot.min') %>
 <script>

layout/_partial/ayer.ejs

@@ -12,7 +12,13 @@
     </div>
     <div class="cover-inner text-center text-white">
       <h1><a href="<%- url_for() %>"><%= config.title %></a></h1>
-      <h2><%= config.subtitle %></h2>
+      <div id="subtitle-box">
+        <% if (theme.subtitle.enable) { %>
+        <span id="subtitle"></span>
+        <% }else{ %>
+          <span id="subtitle"><%= theme.subtitle.text %></span>
+        <% } %>
+      </div>
       <div>
         <% if (theme.cover.logo) { %>
         <img