feat: 在綫聊天新增facebook洽談外掛程式 closed #918

feat: 添加artalk評論 closed #933
fix: 修復 開啟 archor 後， facebook評論加載不正確的 bug
fix: 修復 facebook 評論數無法加載的 bug

layout/includes/third-party/comments/artalk.pug

@@ -0,0 +1,45 @@
+- const { server, site } = theme.artalk
+
+script.
+  function addArtalkSource () {
+    const ele = document.createElement('link')
+    ele.rel = 'stylesheet'
+    ele.href= '!{theme.asset.artalk_css}'
+    document.getElementsByTagName('head')[0].appendChild(ele)
+  }
+
+  function loadArtalk () {
+    function initArtalk () {
+      window.artalkItem = new Artalk({
+        el: '#artalk-wrap',
+        server: '!{server}',
+        site: '!{site}',
+        pageKey: location.pathname,
+        darkMode: document.documentElement.getAttribute('data-theme') === 'dark',
+        countEl: '.artalk-count'
+      })
+    }
+
+    if (typeof window.artalkItem === 'object') setTimeout(()=>{initArtalk()},200)
+    else {
+      addArtalkSource()
+      typeof Artalk !== 'function' ? getScript('!{theme.asset.artalk_js}').then(initArtalk)
+                                  : setTimeout(()=>{initArtalk()},200)
+    }
+  }
+
+  document.getElementById('darkmode').addEventListener('click',()=> {
+    if (typeof window.artalkItem !== 'object') return
+    let isDark = document.documentElement.getAttribute('data-theme') === 'dark'
+    window.artalkItem.setDarkMode(!isDark)
+  })
+
+  
+  if ('!{theme.comments.use[0]}' === 'Artalk' || !!{theme.comments.lazyload}) {
+    if (!{theme.comments.lazyload}) btf.loadComment(document.getElementById('artalk-wrap'), loadArtalk)
+    else loadArtalk()
+  } else {
+    function loadOtherComment () {
+      loadArtalk()
+    }
+  }