[ruby/csv] Fix typos (ruby/csv#236)

ruby/csv@d5e401266f

Author: sampatbadhe

doc/csv/options/generating/write_headers.rdoc

@@ -19,7 +19,7 @@ Without +write_headers+:
 
 With +write_headers+":
   CSV.open(file_path,'w',
-      :write_headers=> true,
+      :write_headers => true,
       :headers => ['Name','Value']
     ) do |csv|
       csv << ['foo', '0']

doc/csv/recipes/generating.rdoc

@@ -146,7 +146,7 @@ This example defines and uses a custom write converter to strip whitespace from
 
 ==== Recipe: Specify Multiple Write Converters
 
-Use option <tt>:write_converters</tt> and multiple custom coverters
+Use option <tt>:write_converters</tt> and multiple custom converters
 to convert field values when generating \CSV.
 
 This example defines and uses two custom write converters to strip and upcase generated fields: