Create greenfield nullable references tutorial

[BillWagner]

This tutorial will show a File / New Project experience in a post-nullable reference world. The goals is to show readers the syntax, and motivate existing C# developers to see a better world without nulls.

[BillWagner]

Proposed sample: Survey results

• The root object is a collection of people who were asked to respond to the survey. Some did, some chose not to respond. (The associated survey results object may be null).
• The survey object has a list of questions. These are non-nullable.
• The response objects have a collection of answers mapped to questions. Each question has an answer. Some are required (answers must be non-nullable). Some are optional (may be null).

The comparison of references that may be null and those that can never be null provides a good example to explain how the feature enables developers to express their designs more clearly.

The nullable objects can show the response rate, both % of people contacted that responded, and % of respondents that answered each optional question. The introduction of nullable / non-nullable reference types points to a different design than you would make with only nullable reference types.