Add initial setup and admin page

templates/initial_setup.html.tera

@@ -0,0 +1,15 @@
+{% extends "_layout" %}
+
+{% block content %}
+<form class="m-3" method="POST" action="/initial_setup">
+  <div class="mb-3">
+    <label for="user" class="form-label">Admin Username</label>
+    <input type="username" class="form-control" id="user" name="admin_username">
+  </div>
+  <div class="mb-3">
+    <label for="pass" class="form-label">Admin Password</label>
+    <input type="password" class="form-control" id="pass" name="admin_password">
+  </div>
+  <button type="submit" class="btn btn-primary">Complete initial setup</button>
+</form>
+{% endblock content %}