[gnome-text-editor] page: add margin to overview map

[Christian Hergert <chergert src gnome org>]

commit f339f17923c3e61ecce5212f4f8bdbf2e4162078
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jun 21 15:03:40 2021 -0700

    page: add margin to overview map
    
    Now that the GtkSourceMap can adjust for margin, we can set this to get a
    more pleasing display.

 src/editor-page.ui | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/editor-page.ui b/src/editor-page.ui
index 2714f08..f6a0591 100644
--- a/src/editor-page.ui
+++ b/src/editor-page.ui
@@ -36,6 +36,7 @@
                 </child>
                 <child>
                   <object class="GtkSourceMap" id="map">
+                    <property name="left-margin">12</property>
                     <property name="hexpand">false</property>
                     <property name="visible">false</property>
                     <property name="view">view</property>