Add child visible support for layers

README.md

@@ -29,6 +29,8 @@ unless they have the following names:
 
 * (visible): The layer is always visible, regardless if it's specified in `#active_layers`
 * (protect): The layer will not be deleted if it is hidden. Good for clone sources.
+* (child visible): The layer will be visible if its parent layer is also made visible. Good if you
+                   break artwork up into multiple layers (inks, colors, shading, etc.)
 
 Hiding/showing layers is the way that you make certain card elements appear/disappear on
 different types of cards with with different properties. You can also replace the text in

lib/svggvs/target.rb

@@ -32,6 +32,18 @@ module SVGGVS
                            end
         end
       end
+
+      loop do
+        any_changed = false
+        css("g[inkscape|groupmode='layer']").each do |layer|
+          if layer['inkscape:label'].include?('(child visible)') && layer['style'] != '' && layer.parent['style'] == ''
+            layer['style'] = ''
+
+            any_changed = true
+          end
+        end
+        break if !any_changed
+      end
     end
 
     def replacements=(replacements)