Add configuration loading + docs + linter fixes.

global.go

@@ -19,6 +19,7 @@ func Parse(cli interface{}, options ...Option) string {
 	return cmd
 }
 
+// FatalIfErrorf terminates with an error message if err != nil.
 func FatalIfErrorf(err error, args ...interface{}) {
 	if App == nil {
 		panic("call kong.Parse() before using kong.FatalIfErrorf()")
@@ -26,6 +27,7 @@ func FatalIfErrorf(err error, args ...interface{}) {
 	App.FatalIfErrorf(err, args...)
 }
 
+// Errorf writes a message to Kong.Stderr with the application name prefixed.
 func Errorf(format string, args ...interface{}) {
 	if App == nil {
 		panic("call kong.Parse() before using kong.Errorf()")
@@ -33,6 +35,7 @@ func Errorf(format string, args ...interface{}) {
 	App.Errorf(format, args...)
 }
 
+// Printf writes a message to Kong.Stdout with the application name prefixed.
 func Printf(format string, args ...interface{}) {
 	if App == nil {
 		panic("call kong.Parse() before using kong.Printf()")