Add metro notification system in JS with styling, fix audio playback before first volume change, change tip.js to export function to register new element with hint.

_includes/header.njk

@@ -8,7 +8,10 @@
                     by: "{{ i18n[langKey].by | safe }}",
                     options: "{{ i18n[langKey].options | safe }}",
                     hideBackground: "{{ i18n[langKey].hideBackground | safe }}",
-                    back: "{{ i18n[langKey].back | safe }}"
+                    back: "{{ i18n[langKey].back | safe }}",
+                    permissionIssue: "{{ i18n[langKey].permissionIssue | safe }}",
+                    permissionIssueNotificationContent: "{{ i18n[langKey].permissionIssueNotificationContent | safe }}",
+                    notificationDefaultHint: "{{ i18n[langKey].notificationDefaultHint | safe }}",
                 }
         </script>
     </div>

_includes/post.njk

@@ -9,7 +9,7 @@ title: Adrian Victor:Blog
     <article>
         <div id="postHeader">
             <h1>{{ postTitle }}</h1>
-            <p>{{ authors or "Adrian Victor" }} - {{ date | postDate }}</p>
+            <p>{{ authors or "Adrian Victor" }} - <b>{{ date | postDate }}</b>{% if lastModified | postDate !==  date | postDate %} ({{ i18n[langKey].lastEditedIn }} {{ lastModified | postDate }}){% endif %}</p>
             {% if altLanguages.length > 0 %}
             {{ i18n[langKey].availableInOtherLanguages }}:
             {% for alt in altLanguages %}