doc: fix typo in contribute.html

Change-Id: Ica27c4a9e4c364d94250aebfc4c2b59cff7f4a8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/258679
Trust: Alberto Donizetti <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: ALTree

doc/contribute.html

@@ -806,10 +806,9 @@ <h3 id="ref_issues">Referencing issues</h3>
 
 <p>
 If the change is a partial step towards the resolution of the issue,
-uses the notation "Updates #12345".
-This will leave a comment in the issue
-linking back to the change in Gerrit, but it will not close the issue
-when the change is applied.
+write "Updates #12345" instead.
+This will leave a comment in the issue linking back to the change in
+Gerrit, but it will not close the issue when the change is applied.
 </p>
 
 <p>