Update README/docs to clarify MacOS Usage

[ILikeTeaALot]

(My code editor appears to have messed with line endings or something in the README making the diff difficult to read... the bit that's changed is:

before:

...

The main struct is MediaControls. In order to create this struct you need a PlatformConfig. This struct contains all of the platform-specific requirements for spawning media controls. Here are the differences between the platforms:

• MacOS: No config needed, but requires a window to be open (#23)

...

after:

...

The main struct is MediaControls. In order to create this struct you need a PlatformConfig. This struct contains all of the platform-specific requirements for spawning media controls. Here are the differences between the platforms:

• MacOS: No config needed, but requires an AppDelegate/winit event loop (an open window is not required.) (#23)

...

(emphasis added for clarity)

[Sinono3]

Yeah, it's fine. Don't know why the line endings were CRLF anyway. Thank you!