Fix gemspec to point to new README format

Author: dmarkow

jquery_mobile_rails.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |s|
   s.description = "JQuery Mobile files for Rails' assets pipeline"
   s.license     = 'MIT'
 
-  s.files = Dir["{app,config,db,lib,vendor}/**/*"] + ["MIT-LICENSE", "Rakefile", "README.rdoc"]
+  s.files = Dir["{app,config,db,lib,vendor}/**/*"] + ["MIT-LICENSE", "Rakefile", "README.md"]
   s.test_files = Dir["test/**/*"]
 
   s.add_dependency "railties", ">= 3.1.0"