Note that commands only work in open PRs

Author: flip1995

homu/html/index.html

@@ -38,6 +38,7 @@ <h3>Commands</h3>
             comments on the PR they refer to. Comments may include multiple commands. Homu will
             only listen to official reviewers that it is configured to listen to. A comment
             must mention the GitHub account Homu is configured to use. (e.g. for the Rust project this is @bors)
+            Note that Homu will only recognize comments in <i>open</i> PRs.
         </p>
 
         <ul>