docs: Minor fix to the README

The `pack:watch` rename missed a spot in the README.

Author: arbrandes

README.md

@@ -78,7 +78,7 @@ This watches for changes in `frontend-base` and rebuilds the packaged tarball on
 ```sh
 nvm use
 npm ci
-npm run dev:pack
+npm run pack:watch
 ```
 
 #### In the consuming application