Update WEBSITE.md

WEBSITE.md

@@ -17,6 +17,6 @@ The automatically-managed files and directories are:
 
 - `versions.js`
 
-*Do not make commits that modify the contents of these automatically managed directories.*
+*Do not make commits that modify the contents of these automatically managed files and directories.*
 
 To locally test changes to the Gen website, check out the `gh-pages` branch, and follow steps 2 and 4 of [Setting up your GitHub Pages site locally with Jekyll](https://help.github.com/en/articles/setting-up-your-github-pages-site-locally-with-jekyll).