Fix typo

Author: Wirone

docs/usage.md

@@ -34,7 +34,7 @@ sudo curl -L --output /usr/local/bin/pie https://github.com/php/pie/releases/lat
 PIE is published as binary-only Docker image, so you can install it easily during your Docker build:
 
 ```Dockerfile
-COPY --form=ghcr.io/php/pie:latest /pie /usr/bin/pie
+COPY --from=ghcr.io/php/pie:latest /pie /usr/bin/pie
 ```
 
 Instead of `latest` you can also use explicit versions like `x.y.z`, `x.y` or `x`, depending on stability level you want to achieve.