add translation

resource/locales/en_US/translation.json

@@ -1,5 +1,6 @@
 {
   "Help": "Help",
+  "view": "View",
   "Edit": "Edit",
   "Delete": "Delete",
   "delete_all": "Delete all",
@@ -424,6 +425,7 @@
     "open_sandbox": "Open Sandbox"
   },
   "hackmd": {
+    "hackmd": "HackMD",
     "not_set_up": "HackMD is not set up.",
     "start_to_edit": "Start to edit with HackMD",
     "clone_page_content": "Click to clone page content and start to edit.",

resource/locales/ja_JP/translation.json

@@ -1,5 +1,6 @@
 {
   "Help": "ヘルプ",
+  "view": "View",
   "Edit": "編集",
   "Delete": "削除",
   "delete_all": "全て削除",
@@ -426,6 +427,7 @@
     "open_sandbox": "Sandbox を開く"
   },
   "hackmd":{
+    "hackmd": "HackMD",
     "not_set_up": "HackMD はセットアップされていません",
     "start_to_edit": "HackMD を開始する",
     "clone_page_content": "ページを複製して編集を開始します",

resource/locales/zh_CN/translation.json

@@ -1,5 +1,6 @@
 {
-	"Help": "帮助",
+  "Help": "帮助",
+  "view": "View",
 	"Edit": "编辑",
 	"Delete": "删除",
 	"delete_all": "删除所有",
@@ -395,6 +396,7 @@
 		"open_sandbox": "开放式沙箱"
 	},
 	"hackmd": {
+    "hackmd": "HackMD",
 		"not_set_up": "HackMD is not set up.",
 		"start_to_edit": "Start to edit with HackMD",
 		"clone_page_content": "Click to clone page content and start to edit.",

src/client/js/components/Navbar/GrowiSubNavigation.jsx

@@ -191,7 +191,7 @@ const GrowiSubNavigation = (props) => {
             <div className="btn-group" role="group" aria-label="three-stranded-button">
               <button type="button" className="btn btn-outline-primary">
                 <i className="icon-control-play icon-fw" />
-                { t('View') }
+                { t('view') }
               </button>
               <button type="button" className="btn btn-outline-primary">
                 <i className="icon-note icon-fw" />
@@ -199,7 +199,7 @@ const GrowiSubNavigation = (props) => {
               </button>
               <button type="button" className="btn btn-outline-primary">
                 <i className="fa fa-fw fa-file-text-o" />
-                { t('HackMD') }
+                { t('hackmd') }
               </button>
             </div>
           </div>