testnet deployment enables staging and production instructions

[dskvr]

Summary

One of the largest hold ups to EOSIO documentation was the lack of a testnet. The lack of which made progressing a user through the entire development experience require the user to deploy a testnet locally, which is not feasible for the majority of the audience.

Some recommended topics to cover:

• Deploying an app to testnet (likely a brand new top level section in "Getting Started")
• Understanding EOSIO Testnet's constraints.
• Virtual instructions for deploying to a production blockchain network powered by EOSIO.

Motivation

Fully document the intended EOSIO development workflow.

Steps to resolve this issue

• [x] Create a new section in "Getting Started"
• [ ] Use @iamveritas's documents prepared a year ago as a first drraft.
• [ ] Create several steps under the "Getting Started" section

Draft the doc

• [ ] Write the doc, determine an appropriate location (likely somewhere in this repo's /docs directory)
• [ ] Set the content_title and link_text variables in the document's frontmatter bloc

Open a pull request

• [ ] Open a pull request with your work, providing a title that describes the problem being solved and including the words "Resolves #[this issue's number]" in the pull request body

[dixia]

This "Create a new section in "Getting Started"" is completed