替换 BootCDN 源为字节跳动源，更新资源版本

去除被黑产供应链投毒的风险，详见 https://www.52pojie.cn/thread-1944970-1-1.html

_config.yml

@@ -100,7 +100,7 @@ paginate_path: /page:num # don't change this unless for special need
 
 ## => Sources
 ##############################
-sources: # bootcdn (default), unpkg
+sources: bytecdn # bytecdn (default), unpkg
 
 
 ## => Sharing

_data/variables.yml

@@ -40,25 +40,25 @@ default:
     search: default
 
 sources:
-  bootcdn:
-    font_awesome: 'https://cdn.bootcdn.net/ajax/libs/font-awesome/5.14.0/css/all.css'
-    jquery: 'https://cdn.bootcdn.net/ajax/libs/jquery/3.1.1/jquery.min.js'
-    leancloud_js_sdk: '//cdn.jsdelivr.net/npm/leancloud-storage@3.13.2/dist/av-min.js'
-    chart: 'https://cdn.bootcdn.net/ajax/libs/Chart.js/2.7.3/Chart.js'
+  bytecdn:
+    font_awesome: 'https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/font-awesome/5.15.4/css/all.css'
+    jquery: 'https://lf6-cdn-tos.bytecdntp.com/cdn/expire-1-M/jquery/3.4.1/jquery.min.js'
+    leancloud_js_sdk: 'https://unpkg.com/leancloud-storage@3.15.0/dist/av-min.js'  # 没有国内 CDN 支持
+    chart: 'https://lf9-cdn-tos.bytecdntp.com/cdn/expire-1-M/Chart.js/2.9.4/Chart.min.js'
     gitalk:
-      js: 'https://cdn.bootcdn.net/ajax/libs/gitalk/1.2.4/gitalk.js'
-      css: 'https://cdn.bootcdn.net/ajax/libs/gitalk/1.2.4/gitalk.css'
-    valine: 'https://cdn.bootcdn.net/ajax/libs/valine/1.4.18/Valine.min.js'
-    mathjax: 'https://cdn.bootcdn.net/ajax/libs/mathjax/2.7.7/config/TeX-MML-AM_CHTML.js'
-    mermaid: 'https://cdn.bootcdn.net/ajax/libs/mermaid/8.1.0/mermaid.min.js'
+      js: 'https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/gitalk/1.7.2/gitalk.min.js'
+      css: 'https://lf6-cdn-tos.bytecdntp.com/cdn/expire-1-M/gitalk/1.7.2/gitalk.min.css'
+    valine: 'https://lf9-cdn-tos.bytecdntp.com/cdn/expire-1-M/valine/1.4.16/Valine.min.js'
+    mathjax: 'https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/mathjax/2.7.9/MathJax.js?config=TeX-MML-AM_CHTML'
+    mermaid: 'https://lf6-cdn-tos.bytecdntp.com/cdn/expire-1-M/mermaid/8.14.0/mermaid.min.js'
   unpkg:
-    font_awesome: 'https://use.fontawesome.com/releases/v5.15.1/css/all.css'
-    jquery: 'https://unpkg.com/jquery@3.3.1/dist/jquery.min.js'
-    leancloud_js_sdk: '//cdn.jsdelivr.net/npm/leancloud-storage@3.13.2/dist/av-min.js'
-    chart: 'https://unpkg.com/chart.js@2.7.2/dist/Chart.min.js'
+    font_awesome: 'https://unpkg.com/@fortawesome/fontawesome-free@5.15.4/css/all.css'
+    jquery: 'https://unpkg.com/jquery@3.4.1/dist/jquery.min.js'
+    leancloud_js_sdk: 'https://unpkg.com/leancloud-storage@3.15.0/dist/av-min.js'
+    chart: 'https://unpkg.com/chart.js@2.9.4/dist/Chart.min.js'
     gitalk:
-      js: 'https://unpkg.com/gitalk@1.2.2/dist/gitalk.min.js'
-      css: 'https://unpkg.com/gitalk@1.2.2/dist/gitalk.css'
-    valine: 'https//unpkg.com/valine/dist/Valine.min.js'
-    mathjax: 'https://unpkg.com/mathjax@2.7.4/unpacked/MathJax.js?config=TeX-MML-AM_CHTML'
-    mermaid: 'https://unpkg.com/mermaid@8.0.0-rc.8/dist/mermaid.min.js'
+      js: 'https://unpkg.com/gitalk@1.7.2/dist/gitalk.min.js'
+      css: 'https://unpkg.com/gitalk@1.7.2/dist/gitalk.css'  # 没有压缩版
+    valine: 'https://unpkg.com/valine@1.4.16/dist/Valine.min.js'
+    mathjax: 'https://www.unpkg.com/mathjax@2.7.9/MathJax.js?config=TeX-MML-AM_CHTML'
+    mermaid: 'https://unpkg.com/mermaid@8.14.0/dist/mermaid.min.js'