Update README with app features and overview

Added a brief description of the app's features and functionality.

Author: hidao80

README.md

@@ -1,5 +1,3 @@
-# Fast Logbook PWA
-
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE) 
 ![PWA](https://img.shields.io/badge/PWA-Yes-4BC51D.svg) 
 ![Lint](https://github.com/hidao80/Fast-logbook-PWA/actions/workflows/lint.yml/badge.svg) 
@@ -9,6 +7,14 @@
 
 ![Accessibility](https://img.shields.io/badge/Accessibility-94-brightgreen?style=flat-square)&emsp;![Best_Practices](https://img.shields.io/badge/Best_Practices-100-brightgreen?style=flat-square)&emsp;![Performance](https://img.shields.io/badge/Performance-93-brightgreen?style=flat-square)&emsp;![SEO](https://img.shields.io/badge/SEO-90-brightgreen?style=flat-square)&emsp;<sub>Measured on Jan 17, 2026 by [Lighthouse-badges](https://github.com/hidao80/lighthouse-badges) — [Measure now!](https://pagespeed.web.dev/analysis?url=https://fast-logbook.netlify.app/)</sub>
 
+**Record with one tap. Instantly tally. No installation required.**
+
+- **Quick**: Instantly stamp with a tap or by pressing the number keys 1-9.
+- **Aggregate**: Instantly calculate totals and grand totals.
+- **Secure**: Data stays 100% in your browser — no server, no account.
+
+# Fast Logbook PWA
+
 ## Overview
 Fast-logbook-PWA is a lightweight PWA for recording and aggregating daily work logs quickly and securely, on any device with a browser.