message: feat(context-menus): add youglish
diff: export function getAllContextMenus () {
  const allContextMenus = {
  - google_page_translate: 'x',
  - youdao_page_translate: 'x',
  - google_search: 'https://www.google.com/#newwindow=1&q=%s',
  baidu_search: 'https://www.baidu.com/s?ie=utf-8&wd=%s',
  + bing_dict: 'https://cn.bing.com/dict/?q=%s',
  bing_search: 'https://www.bing.com/search?q=%s',
  - google_translate: 'https://translate.google.cn/#auto/zh-CN/%s',
  - etymonline: 'http://www.etymonline.com/index.php?search=%s',
  - merriam_webster: 'http://www.merriam-webster.com/dictionary/%s',
  - oxford: 'http://www.oxforddictionaries.com/us/definition/english/%s',
  cambridge: 'http://dictionary.cambridge.org/spellcheck/english-chinese-simplified/?q=%s',
  - youdao: 'http://dict.youdao.com/w/%s',
  dictcn: 'https://dict.eudic.net/dicts/en/%s',
  + etymonline: 'http://www.etymonline.com/index.php?search=%s',
  + google_page_translate: 'x',
  + google_search: 'https://www.google.com/#newwindow=1&q=%s',
  + google_translate: 'https://translate.google.cn/#auto/zh-CN/%s',
  + guoyu: 'https://www.moedict.tw/%s',
  iciba: 'http://www.iciba.com/%s',
  liangan: 'https://www.moedict.tw/~%s',
  - guoyu: 'https://www.moedict.tw/%s',
  longman_business: 'http://www.ldoceonline.com/search/?q=%s',
  - bing_dict: 'https://cn.bing.com/dict/?q=%s'
  + merriam_webster: 'http://www.merriam-webster.com/dictionary/%s',
  + oxford: 'http://www.oxforddictionaries.com/us/definition/english/%s',
  + youdao_page_translate: 'x',
  + youdao: 'http://dict.youdao.com/w/%s',
  + youglish: 'https://youglish.com/search/%s',
  }
  // Just for type check. Keys in allContextMenus are useful so no actual assertion
  