Rakefile : add zip for zipping up _site

.gitignore

@@ -1 +1,2 @@
-_site
+_site
+isotope-site.zip

Rakefile

@@ -20,4 +20,16 @@ task :min do
       f.write min
     end
   end
+end
+
+desc "Zips _site/ into isotope-site.zip"
+task :zip do
+  # makes isotope-site/ directory
+  sh 'mkdir isotope-site;' 
+  # copies _site/
+  sh 'cp -r _site/ isotope-site;'
+  # zips isotope-site/
+  sh 'zip -r isotope-site isotope-site/;' 
+  # removes isotope-site/
+  sh 'rm -rf isotope-site;'
 end