Exclude directories from `follow-file-renames` #4683

Description

following from https://github.com/sindresorhus/refined-github/pull/4677#pullrequestreview-733587222

we should probably skip the feature when we are on folder commit list.

quoting from https://github.com/fregante/github-url-detection/issues/89#issuecomment-901863779

It can be determined from the DOM, ideally from some meta tags in the HEAD, otherwise we just need to look for specific /blob/ links on the page

Example URL

• file commit page : https://github.com/ForkAwesome/Fork-Awesome/commits/master/src/doc/_plugins/site.rb
• directory commit page : https://github.com/ForkAwesome/Fork-Awesome/commits/master/src/doc/_plugins/