Add Codemirror modes

.gitignore

@@ -1,5 +1,6 @@
 /Gemfile.lock
 .bundle/
+.idea
 benchmark/
 lib/linguist/samples.json
 /grammars

lib/linguist/language.rb

@@ -300,6 +300,7 @@ module Linguist
       end
 
       @ace_mode = attributes[:ace_mode]
+      @codemirror_mode = attributes[:codemirror_mode]
       @wrap = attributes[:wrap] || false
 
       # Set legacy search term
@@ -397,6 +398,17 @@ module Linguist
     # Returns a String name or nil
     attr_reader :ace_mode
 
+    # Public: Get Codemirror mode
+    #
+    # Examples
+    #
+    #  # => "nil"
+    #  # => "javascript"
+    #  # => "clike"
+    #
+    # Returns a String name or nil
+    attr_reader :codemirror_mode
+
     # Public: Should language lines be wrapped
     #
     # Returns true or false