先總結一下，改天繼續寫
- Indexed Members and Element Initializers
- Auto-Properties with Initializers
- Primary Constructors
- Static Using Statements
- Declaration Expressions
- Exception-Handling Improvements
- Additional Numeric Literal Formats
- Null-Conditional Operator
- Nameof Expressions
- Expression Bodied Functions and Properties
- Event initializers
- NameOf operator
感覺沒有太大的新功能，都只是讓開發更容易和方便