README.md: Fix dev/unstable install instructions.

Gadgetoid · Gadgetoid · commit fdd33d1aa486 · 2023-04-06T15:52:29.000+01:00
diff --git a/README.md b/README.md
@@ -28,5 +28,5 @@ Latest/development library from GitHub:
 
 * `git clone https://github.com/pimoroni/PROJECT_NAME-python`
 * `cd PROJECT_NAME-python`
-* `sudo ./install.sh`
+* `./install.sh --unstable`
 
