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/error.html

@@ -0,0 +1,16 @@
+{% extends "base.html" %}
+{% block title %}Oops!{% endblock %}
+{% block head %}
+{{ super() }}
+{% endblock %}
+{% block content %}
+<div class="text-center">
+    <h1 class="text-2xl font-bold mb-4">Login failed.</h1>
+    <p class="mb-4">{{ error }}</p>
+    <div class="my-6">
+        <a href='{{ link }}'
+            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">Try
+            again</a>
+    </div>
+</div>
+{% endblock %}