feat: add check for updates button, close #766

src/locales/en.json

@@ -90,6 +90,7 @@
   "Open App Dir": "Open App Dir",
   "Open Core Dir": "Open Core Dir",
   "Open Logs Dir": "Open Logs Dir",
+  "Check for Updates": "Check for Updates",
   "Verge Version": "Verge Version",
   "theme.light": "Light",
   "theme.dark": "Dark",

src/locales/zh.json

@@ -90,6 +90,7 @@
   "Open App Dir": "应用目录",
   "Open Core Dir": "内核目录",
   "Open Logs Dir": "日志目录",
+  "Check for Updates": "检查更新",
   "Verge Version": "应用版本",
   "theme.light": "浅色",
   "theme.dark": "深色",