git ignore files produced by HCFILES (#2084)

Co-authored-by: rmkaplan <69548581+rmkaplan@users.noreply.github.com>

.gitignore

@@ -13,11 +13,9 @@ maiko/
 # normally when you have derived files, you ignore them from git
 # because they will get regenerated when you rebuild.
 # MEDLEY-UTILS HCFILES regenerates
-
-# do not ignore .pdf files after all... rather, [new workflow](scripts/make-gh-pages.md) stores it in the src repository gh-pages branch.
-
-# *.pdf
-# index.html
+# index.html files are also produced by HCFILES
+*.pdf
+index.html
 
 
 # all loadup files