Add document & comment for spec (#703)

* Add document & comment for spec

* remove duplicate field

* use alias

tools/goctl/api/spec/name.go

@@ -5,27 +5,87 @@ func (t PrimitiveType) Name() string {
 	return t.RawName
 }
 
+// Comments returns the comments of struct
+func (t PrimitiveType) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t PrimitiveType) Documents() []string {
+	return nil
+}
+
 // Name returns a structure string, such as User
 func (t DefineStruct) Name() string {
 	return t.RawName
 }
 
+// Comments returns the comments of struct
+func (t DefineStruct) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t DefineStruct) Documents() []string {
+	return t.Docs
+}
+
 // Name returns a map string, such as map[string]int
 func (t MapType) Name() string {
 	return t.RawName
 }
 
+// Comments returns the comments of struct
+func (t MapType) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t MapType) Documents() []string {
+	return nil
+}
+
 // Name returns a slice string, such as []int
 func (t ArrayType) Name() string {
 	return t.RawName
 }
 
+// Comments returns the comments of struct
+func (t ArrayType) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t ArrayType) Documents() []string {
+	return nil
+}
+
 // Name returns a pointer string, such as *User
 func (t PointerType) Name() string {
 	return t.RawName
 }
 
+// Comments returns the comments of struct
+func (t PointerType) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t PointerType) Documents() []string {
+	return nil
+}
+
 // Name returns a interface string, Its fixed value is interface{}
 func (t InterfaceType) Name() string {
 	return t.RawName
 }
+
+// Comments returns the comments of struct
+func (t InterfaceType) Comments() []string {
+	return nil
+}
+
+// Documents returns the documents of struct
+func (t InterfaceType) Documents() []string {
+	return nil
+}