UI Improvements (#7)

* Initial version with UI templates

* Implement basic screens

* Linting & bump to 0.3.0

* Tick off some TODOs

custom_components/auth_oidc/views/welcome.html

@@ -0,0 +1,29 @@
+{% extends "base.html" %}
+{% block title %}OIDC Login{% endblock %}
+{% block head %}
+{{ super() }}
+{% endblock %}
+{% block content %}
+<div class="text-center">
+    <h1 class="text-2xl font-bold mb-4">Home Assistant</h1>
+    <p class="mb-4">You have been invited to login to Home Assistant.<br />Start the login process below.</p>
+
+    <button id="oidc-login-btn"
+        class="w-full py-2 px-4 bg-blue-500 text-white font-semibold rounded-lg shadow-md hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-400 focus:ring-opacity-75">
+        Login with OpenID Connect (SSO)
+    </button>
+
+
+    <p class="mt-6 text-sm">After login, you will be granted a one-time code to login to any device. You may complete
+        this login on your desktop or any mobile browser and then use the token for any desktop or the Home Assistant
+        app.</p>
+</div>
+<script>
+    document.getElementById('oidc-login-btn').addEventListener('click', function () {
+        this.innerHTML = 'Redirecting...';
+        this.disabled = true;
+        this.classList.add('bg-gray-500');
+        window.location.href = '/auth/oidc/redirect';
+    });
+</script>
+{% endblock %}