方便 mirror 之类的平台分发，主要是图片格式 (#840)

* chore: generate img cdn files

.gitignore

@@ -8,4 +8,5 @@ artifacts
 .history
 **node_modules**
 **cache**
-**artifacts**
+**artifacts**
+**readme_mirror.md**

mirror_gen.js

@@ -0,0 +1,68 @@
+const fs = require('fs');
+const path = require('path');
+
+const CDN_PREFIX = 'https://cdn.jsdelivr.net/gh/AmazingAng/WTF-Solidity';
+
+// 递归查找所有的 readme.md 文件
+function findReadmeFiles(dir) {
+    let results = [];
+    const files = fs.readdirSync(dir);
+
+    for (const file of files) {
+        const filePath = path.join(dir, file);
+        const stat = fs.statSync(filePath);
+
+        if (stat.isDirectory() && !file.startsWith('.')) {
+            results = results.concat(findReadmeFiles(filePath));
+        } else if (file.toLowerCase() === 'readme.md') {
+            results.push(filePath);
+        }
+    }
+
+    return results;
+}
+
+// 处理图片链接
+function processImageLinks(content, dirName) {
+    const imageRegex = /!\[(.*?)\]\((\.\/[^)]+)\)/g;
+    return content.replace(imageRegex, (match, altText, imagePath) => {
+        const cleanImagePath = imagePath.replace(/^\.\//, '');
+        const cdnUrl = `${CDN_PREFIX}/${dirName}/${cleanImagePath}`;
+        return `![${altText}](${cdnUrl})`;
+    });
+}
+
+// 删除 frontmatter
+function removeFrontmatter(content) {
+    // 匹配开头的 --- 到结束的 --- 之间的所有内容
+    return content.replace(/^---\n[\s\S]*?\n---\n/, '');
+}
+
+function main() {
+    try {
+        const readmeFiles = findReadmeFiles('.');
+        console.log(`找到 ${readmeFiles.length} 个 readme.md 文件`);
+
+        for (const readmePath of readmeFiles) {
+            let content = fs.readFileSync(readmePath, 'utf-8');
+            const dirName = path.dirname(readmePath).replace(/^\.[\\/]/, '');
+
+            // 先删除 frontmatter
+            content = removeFrontmatter(content);
+            // 再处理图片链接
+            const processedContent = processImageLinks(content, dirName);
+
+            // 只有当内容有变化时才创建新文件
+            if (content !== processedContent) {
+                const mirrorPath = path.join(path.dirname(readmePath), 'readme_mirror.md');
+                fs.writeFileSync(mirrorPath, processedContent, 'utf-8');
+                console.log(`已生成镜像文件: ${mirrorPath}`);
+            }
+        }
+        console.log('处理完成！');
+    } catch (error) {
+        console.error('处理过程中出错：', error);
+    }
+}
+
+main();