Fix setting visibility for tree support settings

These have moved. The Support Structure setting was already present in the support category.

Done as a 5 minute fix while working on the Settings Guide.

resources/setting_visibility/expert.cfg

@@ -238,6 +238,11 @@ support_interface_extruder_nr
 support_roof_extruder_nr
 support_bottom_extruder_nr
 support_structure
+support_tree_angle
+support_tree_branch_distance
+support_tree_branch_diameter
+support_tree_branch_diameter_angle
+support_tree_collision_resolution
 support_type
 support_angle
 support_pattern
@@ -350,12 +355,6 @@ smooth_spiralized_contours
 relative_extrusion
 
 [experimental]
-support_structure
-support_tree_angle
-support_tree_branch_distance
-support_tree_branch_diameter
-support_tree_branch_diameter_angle
-support_tree_collision_resolution
 support_tree_wall_thickness
 support_tree_wall_count
 slicing_tolerance