enables to install fonts via cookbook files

Adding font provider for installation of fonts via cookbook files.
Simply add the font into your cookbook files, depend on the windows cookbook and target the windows_font "your_font.ttf" within your recipe.

You could include Chef::Util::PathHelper and then use ```cleanpath(::File.join(fonts_dir, @new_resource.file))``` here instead. #cleanpath helps avoid having to have a method like win_path everywhere, and Chef::Util::PathHelper provides some other useful path helpers like #validate_path which searches for unicode characters in the path which typically show up when someone uses the wrong number of backslashes in a string.