Fix mod_md link

service/donate-review.md

@@ -76,10 +76,10 @@ the apache configuration uses subdomain-based vhosts. the review-apps use
 domains like `<ci commit ref slug>.donate-review-01.torproject.org`.
 Letsencrypt won't give us a wildcard cert for
 `*.donate-review-01.torproject.org` because it's too many nested subdomains.
-Instead, we use apache's [mod\_md][] to dynamically request Letsencrypt
+Instead, we use apache's [mod\_md][modmd] to dynamically request Letsencrypt
 certificates as-needed for new review-apps
 
-[mod_md]: <https://httpd.apache.org/docs/trunk/mod/mod_md.html>
+[modmd]: <https://httpd.apache.org/docs/trunk/mod/mod_md.html>
 
 ## Services