Blog bottom button links are broken

Created by: sqs

The 2 links at the bottom of each blog post are broken. For example, at https://about.sourcegraph.com/blog/search-multiple-revisions:

• Read more posts goes to https://about.sourcegraph.com/blog/search-multiple-revisions/blog (404)
• Edit this post goes to https://github.com/sourcegraph/about/edit/master/blogposts/search-across-revisions.md (404)