chore: better README with a screenshot

Author: alioguzhan

README.md

@@ -1,3 +1,22 @@
-# TruffleShow
+<div align="center">
+<img src="./src/public/android-chrome-192x192.png" alt="TruffleShow Logo" width="100" height="100">
+<h1>TruffleShow</h1>
+</div>
 
-A simple web viewer for TruffleHog JSON output.
+A simple web viewer for TruffleHog JSON output. 
+
+**Completely client-side**. No data is sent to the server. Actually, there is no server.
+
+- Get the JSON output* from TruffleHog
+- Upload it to TruffleShow.
+- View the results.
+
+Note: TruffleHog produces [a broken JSON file](https://github.com/trufflesecurity/trufflehog/issues/2164). To get a valid JSON file, you can use `jq` like this:
+
+```sh
+trufflehog git https://github.com/trufflesecurity/test_keys --json | jq -s . > trufflehog.json
+```
+
+Screenshot:
+
+![TruffleShow Screenshot](./ss.png)