add example qr code to readme

README.md

@@ -2,4 +2,27 @@
 
 A simple program to print data encoded as a QR code to the terminal.
 
-Usage: `qr_cli "<data to encode>"`
+Example usage: 
+```
+> qr_cli "https://en.wikipedia.org/wiki/QR_code"
+
+
+   █▀▀▀▀▀█ ██▄▀█   ▀  ▀▀ █▀▀▀▀▀█
+   █ ███ █ ▄  █ ▀▀▄ ▄ ▄▀ █ ███ █
+   █ ▀▀▀ █  ▄▄▄▀▀█▀▀█▄█  █ ▀▀▀ █
+   ▀▀▀▀▀▀▀ █ █ ▀▄█▄█▄█▄▀ ▀▀▀▀▀▀▀
+   █▄▀▀▄█▀█▄▀███▀▀▀██▄▄ ▄█▄▄▀ ▀█
+   ▀ █ █▄▀▀▄▀▄▄█▄█▄█ █▄ ▄█▄▀ ▀▀▄
+    ▄▀▄ █▀▄█▄▀█▄▄ █▄█▄▄  ▄▀ ▀█▄▄
+   █▀▀ █ ▀▄██   ▄▀ ▄▀▀▀▀ ▄▄▀ ▀█▀
+    ▄ ▀ ▀▀▄▄▀▄▀█▄ ▀▀▄▀▀█▀ ▀▀█▄█
+   ▀ █▄▀▄▀▀▄▀███  █ ▄█  █▀ ▄ █
+    ▀    ▀ ██   █▄▄▄██▀█▀▀▀███▄▄
+   █▀▀▀▀▀█ █▀▄▀█▀  █ ▄▀█ ▀ ██ █▄
+   █ ███ █ ▄▀ ██▄█▀█▀ ▄██▀██▄▀ ▄
+   █ ▀▀▀ █ ▀▀  ▄   ▄   ▄█ █▄▄▀▄▀
+   ▀▀▀▀▀▀▀ ▀ ▀▀▀ ▀▀   ▀▀      ▀
+
+
+
+```