- remove explicit dependency webrick. it's not needed anymore
- force jekyll-multiple-languages-plugin version to 1.7.0, since
later versions currently break jekyll
- update Gemfile.lock
- Use 'jekyll-feed' plugin to manage RSS feed and remove existing feed.xml file
- Add feed image in main blog tab ('All posts')
The 'jekyll-feed' plugin makes possible for aggregators to automatically detect the existence of a feed (feed_meta tag in header)
and creates a 'feed.atom' file containing the last 20 blog posts and locates it in the root directory. The structure is compatible
with our current system, including the possibility to show a picture if it's included in the post (#1002).
Source: Jekyll complaining at me
```
Please add the following to your Gemfile to avoid polling for changes:
gem 'wdm', '>= 0.1.0' if Gem.win_platform?
```
