Better default handling, more samples

lib/squib/api/text.rb

@@ -8,6 +8,12 @@ module Squib
       raise 'Not implemented!'
     end
 
+    #
+    # font: description string, including family, styles, and size.
+    # 
+    # => e.g. 'Arial bold italic 12'
+    # For the official documentation the string, see the [Pango docs](http://ruby-gnome2.sourceforge.jp/hiki.cgi?Pango%3A%3AFontDescription#style). 
+    # This [description](http://www.pygtk.org/pygtk2reference/class-pangofontdescription.html) is also quite good.
     def text(range: :all, str: '', font: :use_set, x: 0, y: 0, **options)
       range = rangeify(range)
       str = [str] * @cards.size unless str.respond_to? :each