GIF example on homepage does not work
**Steps to reproduce:**
Try and compile the GIF example for C#
Fail with error
```cs
main.cs(96,23): error CS0102: The type `ConsoleApp1.Gif' already contains a definition for `Header'
main.cs(25,30): (Location of the symbol related to previous error)
main.cs(97,30): error CS0102: The type `ConsoleApp1.Gif' already contains a definition for `LogicalScreen'
main.cs(56,30): (Location of the symbol related to previous error)
Compilation failed: 2 error(s), 0 warnings
```

The class for the header type and the getter for the header property in seq conflict