added documentation for struct embeddings

go/02-next-level/02-struct-embedding.go

@@ -11,12 +11,12 @@ func (p Person) Say() {
 }
 
 type Student struct {
-	Person
+	Person //struct Person is embedded
 	Semester int
 }
 
 type Teacher struct {
-	Person
+	Person //struct Person is embedded
 	Subject string
 }
 
@@ -30,9 +30,9 @@ func main() {
 
 	max.Say()
 
-	daniel.Say()
+	daniel.Say() //can be invoked directly on Student
 
-	sebastian.Say()
+	sebastian.Say() //can be invoked directly on Teacher
 
 	max = sebastian.Person