Added support for main article image on the article head

.gitignore

@@ -1,4 +1,5 @@
 __pycache__
 build/
 dist/
+.vscode/
 *.egg-info

madblog/static/css/blog.css

@@ -48,3 +48,14 @@ a:hover {
   padding: 0 .5em;
   overflow: auto;
 }
+
+.main-image-container {
+  width: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.main-image-container img {
+  width: 80%;
+}

madblog/templates/article.html

@@ -34,6 +34,12 @@
             {% endif %}
         {% endif %}
 
+        {% if image %}
+        <div class="main-image-container">
+            <img class="main-image" src="{{ image }}" alt=".">
+        </div>
+        {% endif %}
+
         <div class="content">
             {{ content | safe }}
         </div>