macOS build fails; pkg-config is not available

[dinamic]

I've got webp installed via homebrew:

Warning: webp 1.3.2 is already installed and up-to-date.
To reinstall 1.3.2, run:
  brew reinstall webp

Trying to compile the code gives this error. It seems like it's trying to find the location for pkg-config!?

handler/auth.go:24:2: could not import github.com/kolesa-team/go-webp/encoder (-: exec: "pkg-config": executable file not found in $PATH) (typecheck)
	"github.com/kolesa-team/go-webp/encoder"
	^

Maybe the documentation should be updated to reflect that macOS users need to also install pkg-config.

brew install pkg-config