Updating Documentation for Dir::glob
I updated the Dir:glob documentation (pattern section, backslash subsection).
I escaped the backslash character and surrounded code examples with code tags when they were missing.
This is my first contribution to the Ruby documentation.
Thanks to you and Steve Klabnik for calling for more documentation in Ruby 1.9.3(+).
I will try and do my best to fix typos and formatting error when I spot them.