Update tutorial.html

[WatchfulFox]

When using npm -g to install monaca cli it is not (as least in my instance) added to the path and so seems not to run. I am suggesting adding the following line to ~/.bashrc (or Mac equivalent) to ensure it runs properly after installation in the case of the cli not being recognised:

export PATH="$PATH:/usr/local/lib/node_modules/monaca/bin"