1. Adding link to _config.yml pointing at standard location for online version of Software Carpentry lessons.
2. Adding explanatory comments to various sections in template for home page.
3. Putting div's around each section of setup instructions to make boundaries easier to find.
4. Adding a section to display the Etherpad for the workshop if set.
Add sudo for Linux command call
Merge pull request #2 from r-gaia-cs/add-sudo-for-linux-call

Add sudo for Linux command call
Merge pull request #4 from gvwilson/improving-explanatory-comment-in-index-page

Improving explanatory comments in workshop home page.