``style(external-links.scss, links.ts): 添加对mermaid.js.org链接的支持在exte…

…rnal-links.scss`中为指向`mermaid.js.org`的链接添加了特定的SVG图标，并在`links.ts`中更新了链接检测逻辑，以识别包含`mermaid`的域名。

```

quartz/plugins/transformers/links.ts

@@ -88,7 +88,7 @@ export const CrawlLinks: QuartzTransformerPlugin<Partial<Options>> = (userOpts)
                     domain.includes("obsidian.md") ||
                     domain.includes("wikipedia.org") ||
                     domain.includes("quartz") ||
-                    /^[^@\s]+@[^@\s]+\.[^@\s]+$/.test(domain) // email address
+                    domain.includes("mermaid")
                   )
 
                   if (hasSpecialIcon) {

quartz/styles/external-links.scss

@@ -88,6 +88,10 @@ a.external {
       background-image: url("./static/icon.webp");
     }
 
+    &[href*="mermaid.js.org"]::after {
+      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 32 32'%3E%3Cpath fill='%23fd366e' d='M29.973 4.478A14.24 14.24 0 0 0 16 13.842c-2.107-5.82-7.787-9.628-13.973-9.364a14.25 14.25 0 0 0 6.2 12.36a7.65 7.65 0 0 1 3.316 6.32v4.376h8.916V23.16a7.65 7.65 0 0 1 3.315-6.32a14.25 14.25 0 0 0 6.2-12.36z'/%3E%3C/svg%3E");
+    }
+
     //rss
     &[href*="index.xml"]::after {
       background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 24 24'%3E%3Cpath fill='%23ff5b21' d='M5 3h14a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2m2.5 12A1.5 1.5 0 0 0 6 16.5A1.5 1.5 0 0 0 7.5 18A1.5 1.5 0 0 0 9 16.5A1.5 1.5 0 0 0 7.5 15M6 10v2a6 6 0 0 1 6 6h2a8 8 0 0 0-8-8m0-4v2a10 10 0 0 1 10 10h2A12 12 0 0 0 6 6'/%3E%3C/svg%3E")