Fixed typo.

Author: Clemens Fuchslocher

content/index.page

@@ -8,7 +8,7 @@ filter:
 
 h2. Overview
 
-RSpec is testing tool for the Ruby programming language. Born under the banner of Behaviour-Driven Development, it is designed to make Test-Driven Development a productive and enjoyable experience with features like:
+RSpec is a testing tool for the Ruby programming language. Born under the banner of Behaviour-Driven Development, it is designed to make Test-Driven Development a productive and enjoyable experience with features like:
 
 * a rich command line program (the rspec command)
 * textual descriptions of examples and groups ("rspec-core":http://rubydoc.info/gems/rspec-core/frames)