Fix small typo in user manual
s/statup/startup/
Closes
@@ -146,7 +146,7 @@ title: User Manual
<ol>
<li>
The path specified by the <code class='flag'>--bazelrc=<var>file</var></code>
- statup option. If specified, this option must appear <em>before</em> the
+ startup option. If specified, this option must appear <em>before</em> the
command name (e.g. <code>build</code>)
</li>
<li>
