Implement lazy loading (#188)

templates/activities/_identity.html

@@ -2,7 +2,7 @@
 <div class="post user">
 
     <a href="{{ identity.urls.view }}">
-        <img src="{{ identity.local_icon_url.relative }}" class="icon" alt="Avatar for {{ identity.name_or_handle }}">
+        <img src="{{ identity.local_icon_url.relative }}" class="icon" alt="Avatar for {{ identity.name_or_handle }}" loading="lazy">
     </a>
 
     {% if created %}

templates/activities/_post.html

@@ -3,7 +3,7 @@
 <div class="post {% if reply %}reply{% endif %}" data-takahe-id="{{ post.id }}" role="article" tabindex="0">
 
     <a href="{{ post.author.urls.view }}" tabindex="-1">
-        <img src="{{ post.author.local_icon_url.relative }}" class="icon">
+        <img src="{{ post.author.local_icon_url.relative }}" class="icon" loading="lazy">
     </a>
 
     <time _="on click go url {% if link_original %}{{ post.url }}{% else %}{{ post.urls.view }}{% endif %} then halt">
@@ -79,7 +79,7 @@
             {% for attachment in post.attachments.all %}
               {% if attachment.is_image %}
                 <a href="{{ attachment.full_url.relative }}" class="image">
-                  <img src="{{ attachment.thumbnail_url.relative }}" title="{{ attachment.name }}" alt="{{ attachment.name }}" />
+                  <img src="{{ attachment.thumbnail_url.relative }}" title="{{ attachment.name }}" alt="{{ attachment.name }}" loading="lazy" />
                 </a>
               {% endif %}
             {% endfor %}

templates/activities/follows.html

@@ -17,7 +17,7 @@
     <section class="icon-menu">
         {% for identity in page_obj %}
             <a class="option" href="{{ identity.urls.view }}">
-                <img src="{{ identity.local_icon_url.relative }}">
+                <img src="{{ identity.local_icon_url.relative }}" loading="lazy">
                 <span class="handle">
                     {{ identity.html_name_or_handle }}
                     <small>@{{ identity.handle }}</small>

templates/admin/identities.html

@@ -20,7 +20,7 @@
     <section class="icon-menu">
         {% for identity in page_obj %}
             <a class="option" href="{{ identity.urls.admin_edit }}">
-                <img src="{{ identity.local_icon_url.relative }}" class="icon" alt="Avatar for {{ identity.name_or_handle }}">
+                <img src="{{ identity.local_icon_url.relative }}" class="icon" alt="Avatar for {{ identity.name_or_handle }}" loading="lazy">
                 <span class="handle">
                     {{ identity.html_name_or_handle }}
                     <small>