[gtk+] Fix css documentation typo for color definition

[Matthias Clasen <matthiasc src gnome org>]

commit 07724de3d9ea15f86078be95ee9a90a3ec783a40
Author: Robert Roth <robert roth off gmail com>
Date:   Thu Oct 20 09:17:45 2016 +0300

    Fix css documentation typo for color definition
    
    'ligher' should be 'lighter', of course.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773246

 docs/reference/gtk/css-overview.xml |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/docs/reference/gtk/css-overview.xml b/docs/reference/gtk/css-overview.xml
index 54722ae..9b4444b 100644
--- a/docs/reference/gtk/css-overview.xml
+++ b/docs/reference/gtk/css-overview.xml
@@ -587,7 +587,7 @@ background-color: @bg_color;
       set of base colors.
     </para>
 
-<literallayout><code>〈color expression〉 = ligher(〈color〉) | darker(〈color〉) | shade(〈number〉,〈color〉) | 
alpha(〈number〉,〈color〉) | mix(〈number〉,〈color〉,〈color〉)</code>
+<literallayout><code>〈color expression〉 = lighter(〈color〉) | darker(〈color〉) | shade(〈number〉,〈color〉) | 
alpha(〈number〉,〈color〉) | mix(〈number〉,〈color〉,〈color〉)</code>
 </literallayout>
 
     <para>