MobileShop: Allow add comments to an order

[morggansoft]

Allow the customer to add comments to an order prior to confirming it, for example "do not put salt on the salad" or this other example "do not put sauce on the meat"

[evereq]

@morggansoft see how comment will works https://www.screencast.com/t/002zLzeA in Mobile Shop

[morggansoft]

Hi @evereq, it was great, very easy to use!!
Is it possible to see this comment from the Merchant App?

[evereq]

@morggansoft we have Alish working on comments in Merchant and Admin App, will let you know when it's done 👍

[morggansoft]

Ok, great work @evereq!