A rake task to convert redmine textile markup to markdown

Prior developing this rake script I was using akohlbecker/convert_textile_to_markdown.rake which is using Pandoc for the actual conversion. Pandoc created a lot of artifacts and was creating markdown which caused redmine 3.3.0 to crash. I order to avoid these problems I decided to take a more direct and simplistic approach.

(This rake script is partially based on https://gist.github.com/d3j/95924df9fccc4d381d75)

Copy or symlink the file into the ./lib/tasks/ folder of your redmine installation.

In the root of your redmine installation:

rake -v redmine:textile_to_markdown  RAILS_ENV="production"