feat: add login page

src/pages/login.astro

@@ -0,0 +1,21 @@
+---
+import PageLayout from '../layouts/PageLayout.astro'
+---
+
+<PageLayout pageName="login">
+    <h1>Login</h1>
+
+    <!-- form with username and password, and a button for oauth login -->
+    <form action="/login" method="post">
+        <h3>Accedi con Poisson</h3>
+        <input type="text" id="username" placeholder="Username" name="username" required />
+        <input type="password" id="password" placeholder="Password" name="password" required />
+
+        <button class="primary" type="submit">Login</button>
+
+        <hr />
+        <h3>Accedi con Ateneo</h3>
+        <a href="/auth/ateneo" class="primary" role="button">Login</a>
+    </form>
+    <!-- <span class="material-symbols-outlined">person</span> -->
+</PageLayout>