Use an alternative permalink format for duplicate titles.
Allows using a simple permalink by default, or a dated permalink as needed.
Add permalink_dated.rb file to your jekyll _plugins directory.
Set dated_url: true in a post that you want to retain the date in the URL.
On a site using a simple permalink style, a post with the filename
2013-07-03-meeting-report may have the URL: /blog/meeting-report.
If future posts are to have the same title, then the dated_url field can be set
to retain the date in the URL:
---
layout: post
title: Meeting Report
date: 2013-07-03
dated_url: true
---
The url for this post is /blog/2013-07-03-meeting-report.
The actual format used can be defined in _config.yml with permalink_dated.
Created by Jamie Osborne.