Update guide.html; fix typo

much -> must

Closes #7495.

PiperOrigin-RevId: 235038218

site/docs/guide.html

diff --git a/site/docs/guide.html b/site/docs/guide.html
index 3be0dcd..a393989 100644
--- a/site/docs/guide.html
+++ b/site/docs/guide.html
@@ -851,7 +851,7 @@
   in the order shown below. The options are interpreted in this order, so
   options in later files can override a value from an earlier file if a
   conflict arises. All options to control which of these files are loaded are
-  startup options, which means they much occur after <code>bazel</code> and
+  startup options, which means they must occur after <code>bazel</code> and
   before the command (<code>build</code>, etc).
 </p>
 <ol>