Add comments on public classes and methods

[megahomyak]

Platform.Reflection

• AssemblyExtensions
• DelegateHelpers
• DynamicExtensions
• EnsureExtensions
• FieldInfoExtensions
• ILGeneratorExtensions
• MethodInfoExtensions
• NotSupportedExceptionDelegateFactory
• NumericType
• PropertyInfoExtensions
• TypeBuilderExtensions
• TypeExtensions
• Types
• Types[T1, T2, T3, T4, T5, T6, T7]
• Types[T1, T2, T3, T4, T5, T6]
• Types[T1, T2, T3T4, T5]
• Types[T1, T2, T3, T4]
• Types[T1, T2, T3]
• Types[T1, T2]
• Types[T]