C# 8 Cheatsheet

I have updated the C# 8 Cheatsheet according to the Microsoft documentation:
Front Page:
Back Page:
The cheat sheet includes the following
1) Default interface methods
2) Nullable reference types
3) Pattern matching enhancements
4) Asynchronous streams
5) Using declarations
6) Enhancement of interpolated verbatim strings
7) Null-coalescing assignment
8) Static local functions
9) Indices and ranges
10) Unmanaged constructed types
11) Readonly-Member
12) Stackalloc in nested expressions
13) Disposable ref structs
New features in the cheatsheet: 
-  Null-coalescing assignment
-  Unmanaged constructed types 
-  Readonly-Member