Update documentation for npx create-bento-app

[huuaho]

Currently the documentation says to run the command

npx create-bento-app <Project-Name>

in order to create a bento RI app. However, this is will lead to the error

npm ERR! code E404 npm ERR! 404 Not Found - GET https://registry.npmjs.org/create-bento-app - Not found npm ERR! 404 npm ERR! 404 'create-bento-app@*' is not in this registry. npm ERR! 404 npm ERR! 404 Note that you can also install from a npm ERR! 404 tarball, folder, http url, or git url.

In order to resolve this, we need to specify the directory as seen in this command

npx @bento-core/create-bento-app GMB

The documentation for this script needs to be updated with the proper command including the directory and/or change the backend of where the app is located so that the command would work.