added advice about restarting zk and mysql if not already running

docs/content/Tutorial:-All-About-Queries.md

@@ -14,6 +14,8 @@ Before we start digging into how to query Druid, make sure you've gone through t
 
 Let's start up a simple Druid cluster so we can query all the things.
 
+Note: If Zookeeper and MySQL aren't running, you'll have to start them again as described in [The Druid Cluster](Tutorial%3A-The-Druid-Cluster.html).
+
 To start a Coordinator node:
 
 ```bash

docs/content/Tutorial:-Loading-Your-Data-Part-1.md

@@ -66,6 +66,8 @@ There are five data points spread across the day of 2013-08-31. Talk about big d
 
 In order to ingest and query this data, we are going to need to run a historical node, a coordinator node, and an indexing service to run the batch ingestion.
 
+Note: If Zookeeper and MySQL aren't running, you'll have to start them again as described in [The Druid Cluster](Tutorial%3A-The-Druid-Cluster.html).
+
 #### Starting a Local Indexing Service
 
 The simplest indexing service we can start up is to run an [overlord](Indexing-Service.html) node in local mode. You can do so by issuing:

docs/content/Tutorial:-Loading-Your-Data-Part-2.md

@@ -231,6 +231,8 @@ The following events should exist in the file:
 
 To index the data, we are going to need an indexing service, a historical node, and a coordinator node.
 
+Note: If Zookeeper and MySQL aren't running, you'll have to start them again as described in [The Druid Cluster](Tutorial%3A-The-Druid-Cluster.html).
+
 To start the Indexing Service:
 
 ```bash