Add markers using new Pango support

dotfiles/i3/config

 bindsym $mod+backslash               mode "mark"
 
 mode "mark" {
+  set $pass     "<span foreground='lime'></span> %title"
+  set $warn     "<span foreground='orange'></span> %title"
+  set $fail     "<span foreground='red'></span> %title"
+  set $strike   "<s>%title</s>"
+  set $unders   "<u>%title</u>"
+  set $italic   "<i>%title</i>"
+  set $normal   "%title"
+
   bindsym m     exec i3-winmark mark   ; mode "default"
   bindsym u     exec i3-winmark unmark ; mode "default"
   bindsym g     exec i3-winmark goto   ; mode "default"
 
-  bindsym $mod+backslash mode "default"
-  bindsym Escape mode "default"
-  bindsym Return mode "default"
+  bindsym p             title_format $pass   ; mode "default"
+  bindsym bracketleft   title_format $warn   ; mode "default"
+  bindsym bracketright  title_format $fail   ; mode "default"
+
+  bindsym BackSpace     title_format $strike ; mode "default"
+  bindsym equal         title_format $unders ; mode "default"
+  bindsym minus         title_format $italic ; mode "default"
+
+  bindsym space         title_format $normal ; mode "default"
+  bindsym backslash     title_format $normal ; mode "default"
+
+  bindsym $mod+backslash    mode "default"
+  bindsym Escape            mode "default"
+  bindsym Return            mode "default"
 }