Better document package building decisions

[andreabadesso]

          question(non-blocking): Should we add these instructions to a document on the repository itself?

          There seem to be many of those small details that can break the production environment and delay future maintenance releases if left unchecked.

Originally posted by @tuliomir in #170 (comment)

We should create a document describing the details needed for this project to build, like:

• wallet-lib must be a peerDependency to prevent bitcore-lib from failing because of multiple instances of it.
• tsconfig from the common module is being built during the build process of the packages