fix(includes): Support including hidden files
fix(includes): Support including hidden files

When everything was mixed into `_layouts`, people marked their includes
with a `_` prefix.  This caused them not to be found when migrated over.

This probably means `.` files are visible.  Its unlikely there will be
ones here that will cause problems, so it should be fine.

cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs