Update downloads.html

Add links for Shoes 3.2 - Hopefully I didn't make any mistakes.
Add .html to the buttons links so localhost copy works.
Mention Shoes 3.2 github site
Add link to Shoes 3.2 blog
Update for Shoes 3.2. change download for 3.2.12
update for Shoes 3.2.13
Merge pull request #55 from ccoupe/gh-pages

Update downloads.html to include Shoes 3.2