Added trivial web ui.

templates/base.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>ledger</title>
+    <script src="https://cdn.tailwindcss.com"></script>
+    <script src="https://unpkg.com/htmx.org@1.8.5"></script>
+  </head>
+
+  <body>{% block body %}{% endblock %}</body>
+
+</html>

templates/index.html

@@ -0,0 +1,5 @@
+{% extends "base.html" %}
+
+{% block body %}
+<h1>Hello World!</h1>
+{% endblock %}