Add ConfigFlag for loading configuration through a flag.

hooks.go

@@ -0,0 +1,19 @@
+package kong
+
+// BeforeResolve is a documentation-only interface describing hooks that run before values are set.
+type BeforeResolve interface {
+	// This is not the correct signature - see README for details.
+	BeforeResolve(args ...interface{}) error
+}
+
+// BeforeApply is a documentation-only interface describing hooks that run before values are set.
+type BeforeApply interface {
+	// This is not the correct signature - see README for details.
+	BeforeApply(args ...interface{}) error
+}
+
+// AfterApply is a documentation-only interface describing hooks that run after values are set.
+type AfterApply interface {
+	// This is not the correct signature - see README for details.
+	AfterApply(args ...interface{}) error
+}