Add .clang-format configuration

This is a first draft of a .clang-format configuration file, which I believe is close to the dolphin style.
Wanting feedback/updates to eventually have a config that matches the dolphin style
Issues that I've noticed:

end of line comments are not aligned by formatter when within struct
#defines are not aligned

#define foo  bar
#define fooo bar

const initializer and enum brace style is incorrect
enum name
{
   VALUE0,
  ...
  VALUE9
}

is restyled as

enum name
{ VALUE0,
  ...
  VALUE9 }