Add listing

src/main/resources/templates/admin.html

@@ -27,9 +27,7 @@
         </div>
         <div>
             <h3>Assets</h3>
-            <input id="asset-url" placeholder="Asset URL" />
-            <input id="asset-width" placeholder="Width" type="number" value="600" />
-            <input id="asset-height" placeholder="Height" type="number" value="400" />
+            <input id="asset-file" type="file" accept="image/*" />
             <button onclick="uploadAsset()">Upload</button>
             <ul id="asset-list"></ul>
         </div>