Show workspace name instead of index

By that workspaces with no indices are displayed as their name instead
of "-1".

.config/polybar/config

@@ -48,22 +48,22 @@ index-sort = true
 wrapping-scroll = false
 
 ; focused = Active workspace on focused monitor
-label-focused = %index%
+label-focused = %name%
 label-focused-background = ${colors.background-alt}
 label-focused-underline= ${colors.primary}
 label-focused-padding = 1
 
 ; unfocused = Inactive workspace on any monitor
-label-unfocused = %index%
+label-unfocused = %name%
 label-unfocused-padding = ${self.label-focused-padding}
 
 ; visible = Active workspace on unfocused monitor
-label-visible = %index%
+label-visible = %name%
 label-visible-underline = ${colors.secondary}
 label-visible-padding = ${self.label-focused-padding}
 
 ; urgent = Workspace with urgency hint set
-label-urgent = %index%
+label-urgent = %name%
 label-urgent-background = ${colors.alert}
 label-urgent-padding = ${self.label-focused-padding}