How to change the style of the email template of the digest?

Development
18

I tried something similar for ActionViews but it did not work (need it to change the template for user notification emails)

::ActionView::Base.prepend_view_path File.expand_path(“../custom_views”, FILE)

Tried this as well (from here)
::ActionViews::ViewPaths.prepend_view_path File.expand_path(“../custom_views”, FILE)

Any ideas? New to Ruby/Rails so pardon my mistakes.

Edit: Not working means discourse won’t start.