allow crawling of commit page but not patch/diffs

Commit page has valuable information that search engines should be allowed to crawl however the .patch and .diff pages have no new information that is not on commit page

public/robots.txt

@@ -38,7 +38,8 @@ Disallow: /*/*/edit
 Disallow: /*/*/raw
 Disallow: /*/*/blame
 Disallow: /*/*/commits/*/*
-Disallow: /*/*/commit
+Disallow: /*/*/commit/*.patch
+Disallow: /*/*/commit/*.diff
 Disallow: /*/*/compare
 Disallow: /*/*/branches/new
 Disallow: /*/*/tags/new