Add power_management.md to docs.json

Add power management tutorial to docs.json.

Author: Amanda Butler

docs.json

@@ -1058,6 +1058,9 @@
                         },
                         {
                             "path": "docs/tutorials/optimize/memory/runtime_stats.md"
+                        },
+                        {
+                            "path": "docs/tutorials/optimize/power/power_manage.md"
                         }
                     ]
                 },