provide definitions for values of 20.378 style:text-underline-style

Replace "The defined value for the style:text-underline-style attribute is none: text has no underlining. The underlining text styles referenced by the values dash, dot-dash, dot-dot-dash, dotted, long-dash, solid and wave, are implementation defined." by "The defined values for the style:text-overline-style are: none: text has no underlining. dash: text has a dashed line underlining it. dot-dash: text has a line whose repeating pattern is a dot followed by a dash underlining it. dot-dot-dash: text has a line whose repeating pattern is two dots followed by a dash underlining it. dotted: text has a dotted line underlining it. long-dash: text has a dashed line whose dashes are longer than the ones from the dashed line for value dash underlining it. solid: text has a solid line underlining it. wave: text has a wavy line underlining it. Note: These definitions are based on the text decoration style 'text-underline-style' from CSS3 Text Module, http://www.w3.org/TR/2003/CR-css3-text-20030514 , W3C, 2003, §9.2"