[pango/line-underline: 12/15] Document new underline values

[Matthias Clasen <matthiasc src gnome org>]

commit 2df4fbc731f7cdd80c16507cfa102bcaf9192fc3
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Aug 19 23:52:27 2019 +0200

    Document new underline values

 pango/pango-markup.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/pango/pango-markup.c b/pango/pango-markup.c
index c8499ced..cdea3a98 100644
--- a/pango/pango-markup.c
+++ b/pango/pango-markup.c
@@ -128,7 +128,8 @@
  *   integer between 1 and 65536 or a percentage value like '50%'.
  *
  * underline
- * : One of 'none', 'single', 'double', 'low', 'error'
+ * : One of 'none', 'single', 'double', 'low', 'error',
+ *   'single-line', 'double-line' or 'error-line'.
  *
  * underline_color
  * : The color of underlines; an RGB color