config: fix example config indentation

config.json.example

@@ -56,13 +56,13 @@
       "separator": "or"
     },
     "sleep": {
-        "commands": ["sleep", "wake up"],
-        "sleep_time": 23,
-        "wakeup_time": 7,
-        "snore": "Zzzz",
-        "sleep_message": "/me falls asleep",
-        "wakeup_message": "/me wakes up",
-        "snore_rate": 1.0
+      "commands": ["sleep", "wake up"],
+      "sleep_time": 23,
+      "wakeup_time": 7,
+      "snore": "Zzzz",
+      "sleep_message": "/me falls asleep",
+      "wakeup_message": "/me wakes up",
+      "snore_rate": 1.0
     },
     "wikipedia": {
       "commands": ["science", "define"],