Factor out the update button into its own small template

For code reuse, you know

templates/account.html

@@ -1,6 +1,7 @@
 {% extends 'layout.html' %}
 {% block main_content %}
 <h1>{{ account.name }}</h1>
+{% include 'update_button.html' %}
 <table class="table">
   <tr><td>Current balance</td><td>{{ account.balance }}</td></tr>
   <tr><td>Last updated</td><td>{{ account.last_updated }}</td></tr>

templates/accounts.html

@@ -11,10 +11,7 @@
     <td>{{ account.source.name }}</td>
     <td>{{ account.last_updated }}</td>
     <td>
-      <form method="POST" action="/update/">
-        <input type="hidden" name="account_uuid" value="{{ account.uuid }}"></input>
-        <input type="submit" value="Update" class="btn btn-primary"></input>
-      </form>
+      {% include 'update_button.html' %}
     </td>
   </tr>
   {% endfor %}

templates/update_button.html

@@ -0,0 +1,4 @@
+<form method="POST" action="/update/">
+  <input type="hidden" name="account_uuid" value="{{ account.uuid }}"></input>
+  <input type="submit" value="Update" class="btn btn-primary"></input>
+</form>