node-executors-help: clarify what an agent is
the second build could take advantage of the spare I/O capacity at that
moment.
<p>
- Agents must have at least one executor. To temporarily prevent any builds from
- being executed on an agent, use the <i>Mark this node temporarily offline</i>
- button on the agent's page.
+ Agents (nodes that are not the master) must have at least one executor.
+ To temporarily prevent any builds from being executed on an agent, use the
+ <i>Mark this node temporarily offline</i> button on the agent's page.
<p>
This does not apply to the Jenkins master &mdash; setting the number of
executors to zero will prevent any builds from being executed on the master.
