Ported login page.

- Only the basic form atm. Backend still needs to be ported.

src/routes/admin/login.svelte

@@ -0,0 +1,25 @@
+<script>
+    import Banner from '../../components/banner.svelte'
+</script>
+
+<Banner/>
+
+<main class="container">
+  <form class="form-signin" action="login.php" method="post">
+    <div class="form-label-group">
+      <label for="username">Username</label>
+      <input type="text" id="username" class="form-control" name="username" placeholder="Username" required autofocus>
+    </div>
+
+    <div class="form-label-group">
+      <label for="inputPassword">Password</label>
+      <input type="password" id="password" class="form-control" name="password" placeholder="Password" required>
+    </div>
+
+    <div class="custom-control custom-checkbox mb-3">
+      <input type="checkbox" class="custom-control-input" id="customCheck1">
+      <label class="custom-control-label" for="customCheck1">Remember password</label>
+    </div>
+    <button class="btn btn-lg btn-primary btn-block text-uppercase" type="submit">Sign in</button>
+  </form>
+</main>