doc: remove mention of <pkg> arg for run-script

It looks like it was not updated with current `npm run-script` syntax,
since it now acceps only one parameter.

If I am not wrong, running scripts of `<pkg>` dependencies was supported
in previous versions (what a pity it was removed), so I updated
documentation.

Reviewed-By: @zkat
Credit: @fibo
PR-URL: #12776

Author: fibo

doc/misc/npm-scripts.md

@@ -34,7 +34,7 @@ following scripts:
   stop and start scripts if no `restart` script is provided.
 
 Additionally, arbitrary scripts can be executed by running `npm
-run-script <pkg> <stage>`. *Pre* and *post* commands with matching
+run-script <stage>`. *Pre* and *post* commands with matching
 names will be run for those as well (e.g. `premyscript`, `myscript`,
 `postmyscript`).