Cleanup: rename variables for gizmo templates

The abbreviation was from 'manipulator',
which was changed to gizmo during development.

Also correct operator description.

release/scripts/templates_py/gizmo_operator_target.py

@@ -24,27 +24,27 @@ class MyCameraWidgetGroup(GizmoGroup):
     def setup(self, context):
         # Run an operator using the dial gizmo
         ob = context.object
-        mpr = self.gizmos.new("GIZMO_GT_dial_3d")
-        props = mpr.target_set_operator("transform.rotate")
+        gz = self.gizmos.new("GIZMO_GT_dial_3d")
+        props = gz.target_set_operator("transform.rotate")
         props.constraint_axis = False, False, True
         props.orient_type = 'LOCAL'
         props.release_confirm = True
 
-        mpr.matrix_basis = ob.matrix_world.normalized()
-        mpr.line_width = 3
+        gz.matrix_basis = ob.matrix_world.normalized()
+        gz.line_width = 3
 
-        mpr.color = 0.8, 0.8, 0.8
-        mpr.alpha = 0.5
+        gz.color = 0.8, 0.8, 0.8
+        gz.alpha = 0.5
 
-        mpr.color_highlight = 1.0, 1.0, 1.0
-        mpr.alpha_highlight = 1.0
+        gz.color_highlight = 1.0, 1.0, 1.0
+        gz.alpha_highlight = 1.0
 
-        self.roll_widget = mpr
+        self.roll_gizmo = gz
 
     def refresh(self, context):
         ob = context.object
-        mpr = self.roll_widget
-        mpr.matrix_basis = ob.matrix_world.normalized()
+        gz = self.roll_gizmo
+        gz.matrix_basis = ob.matrix_world.normalized()
 
 
 bpy.utils.register_class(MyCameraWidgetGroup)