Add missing description of label on API (#7159)

* add missing description of label on API

* fix comment head

* fix swagger

modules/structs/issue_label.go

@@ -1,4 +1,5 @@
 // Copyright 2016 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
@@ -10,8 +11,9 @@ type Label struct {
 	ID   int64  `json:"id"`
 	Name string `json:"name"`
 	// example: 00aabb
-	Color string `json:"color"`
-	URL   string `json:"url"`
+	Color       string `json:"color"`
+	Description string `json:"description"`
+	URL         string `json:"url"`
 }
 
 // CreateLabelOption options for creating a label
@@ -20,13 +22,15 @@ type CreateLabelOption struct {
 	Name string `json:"name" binding:"Required"`
 	// required:true
 	// example: #00aabb
-	Color string `json:"color" binding:"Required;Size(7)"`
+	Color       string `json:"color" binding:"Required;Size(7)"`
+	Description string `json:"description"`
 }
 
 // EditLabelOption options for editing a label
 type EditLabelOption struct {
-	Name  *string `json:"name"`
-	Color *string `json:"color"`
+	Name        *string `json:"name"`
+	Color       *string `json:"color"`
+	Description *string `json:"description"`
 }
 
 // IssueLabelsOption a collection of labels