[gtk/css-line-height2: 11/12] gtk-demo: Add a line height demo

[Matthias Clasen <matthiasc src gnome org>]

commit ab09bd04022e4171269bed36500e8c1afb4ed907
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Aug 22 13:31:16 2021 -0400

    gtk-demo: Add a line height demo
    
    Add an example for widely spaced text to the markup demo.

 demos/gtk-demo/markup.txt | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/demos/gtk-demo/markup.txt b/demos/gtk-demo/markup.txt
index c850fd8c0b..9e42a399a6 100644
--- a/demos/gtk-demo/markup.txt
+++ b/demos/gtk-demo/markup.txt
@@ -18,3 +18,6 @@ Shortcuts: <tt>Monospace</tt> – <b>Bold</b> – <i>Italic</i> – <big>Big</bi
 <span allow_breaks="false">A</span> hy­phen­ation al­go­rithm is a set of rules, espe­ci­ally one co­di­fied 
for im­ple­men­tation in a com­pu­ter pro­gram, that de­ci­des at which points a word can be bro­ken over two 
lines with a hy­phen. For ex­am­ple, a hy­phen­ation al­go­rithm might de­cide that im­peach­ment can be 
broken as <span allow_breaks="false">impeach‧ment</span> or <span allow_breaks="false">im‧peachment</span> 
but not <span allow_breaks="false">impe‧achment.</span>
 
 <span insert_hyphens="false">one/two three/four five/six seven/eight nine/ten</span>
+
+<span line_height='1.33'>Line height: This is an example of widely spaced text. It was achieved by setting 
the line-height factor to 1.33. You can set the line-height factor to any value between 0 and 10.
+Note that the line height affects the spacing between paragraphs as well as between the wrapped lines inside 
a paragraph.</span>