breaking changes: cdn 可一鍵設置 本地文件/可單獨配置主題文件，第三方文件的 cdn

breaking changes: 移除 utterances，giscus， addtoany， busuanzi 的 cdn 配置

layout/includes/third-party/aplayer.pug

@@ -1,3 +1,3 @@
-link(rel='stylesheet' href=url_for(theme.CDN.aplayer_css) media="print" onload="this.media='all'")
-script(src=url_for(theme.CDN.aplayer_js))
-script(src=url_for(theme.CDN.meting_js))
+link(rel='stylesheet' href=url_for(theme.asset.aplayer_css) media="print" onload="this.media='all'")
+script(src=url_for(theme.asset.aplayer_js))
+script(src=url_for(theme.asset.meting_js))

layout/includes/third-party/card-post-count/twikoo.pug

@@ -28,7 +28,7 @@ script.
         if (typeof twikoo === 'object') {
           runTwikoo()
         } else {
-          getScript('!{theme.CDN.twikoo}').then(runTwikoo)
+          getScript('!{theme.asset.twikoo}').then(runTwikoo)
         }
     }
 

layout/includes/third-party/card-post-count/valine.pug

@@ -12,7 +12,7 @@ script.
       }
 
       if (typeof Valine === 'function') initValine() 
-      else getScript('!{url_for(theme.CDN.valine)}').then(initValine)
+      else getScript('!{url_for(theme.asset.valine)}').then(initValine)
     }
 
     window.pjax ? loadValine() : window.addEventListener('load', loadValine)