docs(run): add --sequential

Author: PeterCardenas

docs/cli/run.md

@@ -109,6 +109,11 @@ immediately in all matching packages with prefixed streaming output. This is the
 preferred flag for long-running processes over many packages, for instance, a
 lengthy build process.
 
+### --sequential
+
+Run scripts one after another in a blocking manner rather than concurrently. Note
+that there are no guarantees that the scripts will run in topological sort order.
+
 ### --stream
 
 Stream output from child processes immediately, prefixed with the originating