Tweak workspaces run doc to clarify gotcha with global scripts

Author: dobesv

packages/plugin-workspace-tools/sources/commands/foreach.ts

@@ -44,7 +44,7 @@ export default class WorkspacesForeachCommand extends BaseCommand {
 
       The \`-v,--verbose\` flag can be passed up to twice: once to prefix output lines with the originating workspace's name, and again to include start/finish/timing log lines. Maximum verbosity is enabled by default in terminal environments.
 
-      If the command is \`run\` and the script being run does not exist the child workspace will be skipped without error.
+      If the command is \`run\` and the script being run does not exist the child workspace will be skipped without error.  Note that if the script has a \`:\` in the name, it is considered to exist on all workspaces if any workspace has a script with that name.
     `,
     examples: [[
       `Publish all packages`,