use docker command instead of custom dk alias

Co-authored-by: Nathanaël <7300309+nathanael-h@users.noreply.github.com>
Signed-off-by: Gaëtan Lehmann <glehmann@users.noreply.github.com>

Author: glehmann

scripts/pkg_in_pipe/README.md

@@ -10,5 +10,5 @@ An environmnt variable `PLANE_TOKEN` must be defined when running the generator.
 
 ```sh
 docker build -f pkg_in_pipe .
-dk run -v ~/.koji:/root/.koji:z -e PLANE_TOKEN=<plane token> -v /out/dir:/output:z pkg_in_pipe /output/index.html
+docker run -v ~/.koji:/root/.koji:z -e PLANE_TOKEN=<plane token> -v /out/dir:/output:z pkg_in_pipe /output/index.html
 ```