Change rdiscount for redcarpet

Author: edgurgel

README.markdown

@@ -32,10 +32,10 @@ Development is done in the `next` branch, while `master` contains the docs and g
 
 3. Test it locally
 
-   You need to install `jekyll` and `rdiscount`
+   You need to install `jekyll` and `redcarpet`
 
    ```shell
-   $ gem install jekyll rdiscount
+   $ gem install jekyll redcarpet
    $ jekyll serve # check localhost:4000
    ```
 

_config.yml

@@ -1,3 +1,3 @@
-markdown: rdiscount
+markdown: redcarpet
 pygments: true
 permalink: /blog/:year/:month/:day/:title