Also util files to start only "external containers"

# Conflicts:
#	docs/architecting-and-developing-containerized-and-microservice-based-net-applications-ebook-early-draft.pdf
#	src/Services/Ordering/Ordering.API/Startup.cs

Also similar changes at the CreateOrderCommand
Plus an update to the README.md for GitHub

Solving #9

Set the fields to explicit private
Using .ToReadOnly(), but still might need to use List<> instead HashSet<> so we won't need the .ToList() conversion which is "expensive"..

- Update dockerfile to asp.net 1.1 in ordering

Refactoring related to OrderCommand (instead NewOrderCommand)
Refactoring in Buyer.IdentityGuid instead of fullname variables..

Also, showing Repository Interfaces as RepositoryContracts.