feat: remove unused action in form

src/main/resources/templates/add.html

@@ -20,7 +20,7 @@
                 how to use it.
             </p>
 
-            <form action="/api/add" method="post">
+            <form>
                 <span>
                     <label for="title">Title</label>
                     <input type="text" name="title" id="title" minlength="1" maxlength="50" required>