docs: update font and cdn (#696)

Signed-off-by: Carson Yang <yangchuansheng33@gmail.com>

docSite/static/js/jsdelivr-auto-fallback.js

@@ -0,0 +1,182 @@
+((document) => {
+    'use strict';
+    let fastNode;
+    let failed;
+    let isRunning;
+    const DEST_LIST = [
+      'cdn.jsdelivr.net',
+      'jsd.cdn.zzko.cn',
+      'cdn.jsdelivr.us',
+      'jsd.onmicrosoft.cn',
+      'fastly.jsdelivr.net',
+      'gcore.jsdelivr.net'
+    ];
+    const PREFIX = '//';
+    const SOURCE = DEST_LIST[0];
+    const starTime = Date.now();
+    const TIMEOUT = 2000;
+    const STORE_KEY = 'jsdelivr-auto-fallback';
+    const TEST_PATH = '/gh/PipecraftNet/jsdelivr-auto-fallback@main/empty.css?';
+    const shouldReplace = (text) => text && text.includes(PREFIX + SOURCE);
+    const replace = (text) => text.replace(PREFIX + SOURCE, PREFIX + fastNode);
+    const setTimeout = window.setTimeout;
+    const $ = document.querySelectorAll.bind(document);
+  
+    const replaceElementSrc = () => {
+      let element;
+      let value;
+      for (element of $('link[rel="stylesheet"]')) {
+        value = element.href;
+        if (shouldReplace(value) && !value.includes(TEST_PATH)) {
+          element.href = replace(value);
+        }
+      }
+  
+      for (element of $('script')) {
+        value = element.src;
+        if (shouldReplace(value)) {
+          const newNode = document.createElement('script');
+          newNode.src = replace(value);
+          element.defer = true;
+          element.src = '';
+          element.before(newNode);
+          element.remove();
+        }
+      }
+  
+      for (element of $('img')) {
+        value = element.src;
+        if (shouldReplace(value)) {
+          // Used to cancel loading. Without this line it will remain pending status.
+          element.src = '';
+          element.src = replace(value);
+        }
+      }
+  
+      // All elements that have a style attribute
+      for (element of $('*[style]')) {
+        value = element.getAttribute('style');
+        if (shouldReplace(value)) {
+          element.setAttribute('style', replace(value));
+        }
+      }
+  
+      for (element of $('style')) {
+        value = element.innerHTML;
+        if (shouldReplace(value)) {
+          element.innerHTML = replace(value);
+        }
+      }
+    };
+  
+    const tryReplace = () => {
+      if (!isRunning && failed && fastNode) {
+        console.warn(SOURCE + ' is not available. Use ' + fastNode);
+        isRunning = true;
+        setTimeout(replaceElementSrc, 0);
+        // Some need to wait for a while
+        setTimeout(replaceElementSrc, 20);
+        // Replace dynamically added elements
+        setInterval(replaceElementSrc, 500);
+      }
+    };
+  
+    const checkAvailable = (url, callback) => {
+      let timeoutId;
+      const newNode = document.createElement('link');
+      const handleResult = (isSuccess) => {
+        if (!timeoutId) {
+          return;
+        }
+  
+        clearTimeout(timeoutId);
+        timeoutId = 0;
+        // Used to cancel loading. Without this line it will remain pending status.
+        if (!isSuccess) newNode.href = 'data:text/css;base64,';
+        newNode.remove();
+        callback(isSuccess);
+      };
+  
+      timeoutId = setTimeout(handleResult, TIMEOUT);
+  
+      newNode.addEventListener('error', () => handleResult(false));
+      newNode.addEventListener('load', () => handleResult(true));
+      newNode.rel = 'stylesheet';
+      newNode.text = 'text/css';
+      newNode.href = url + TEST_PATH + starTime;
+      document.head.insertAdjacentElement('afterbegin', newNode);
+    };
+  
+    const cached = (() => {
+      try {
+        return Object.assign(
+          {},
+          JSON.parse(localStorage.getItem(STORE_KEY) || '{}')
+        );
+      } catch {
+        return {};
+      }
+    })();
+  
+    const main = () => {
+      cached.time = starTime;
+      cached.failed = false;
+      cached.fastNode = null;
+  
+      for (const url of DEST_LIST) {
+        checkAvailable('https://' + url, (isAvailable) => {
+          // console.log(url, Date.now() - starTime, Boolean(isAvailable));
+          if (!isAvailable && url === SOURCE) {
+            failed = true;
+            cached.failed = true;
+          }
+  
+          if (isAvailable && !fastNode) {
+            fastNode = url;
+          }
+  
+          if (isAvailable && !cached.fastNode) {
+            cached.fastNode = url;
+          }
+  
+          tryReplace();
+        });
+      }
+  
+      setTimeout(() => {
+        // If all domains are timeout
+        if (failed && !fastNode) {
+          fastNode = DEST_LIST[1];
+          tryReplace();
+        }
+  
+        localStorage.setItem(STORE_KEY, JSON.stringify(cached));
+      }, TIMEOUT + 100);
+    };
+  
+    if (
+      cached.time &&
+      starTime - cached.time < 60 * 60 * 1000 &&
+      cached.failed &&
+      cached.fastNode
+    ) {
+      failed = true;
+      fastNode = cached.fastNode;
+      tryReplace();
+      setTimeout(main, 1000);
+    } else if (document.head) {
+      main();
+    } else {
+      const observer = new MutationObserver(() => {
+        if (document.head) {
+          observer.disconnect();
+          main();
+        }
+      });
+      const observerOptions = {
+        childList: true,
+        subtree: true
+      };
+      observer.observe(document, observerOptions);
+    }
+  })(document);