Remove config/secrets.yml

Rails no longer generates this file with sensitive secrets (default now is to do `secret_key_base: <%= ENV["SECRET_KEY_BASE"] %>` in production).

Rails.gitignore

@@ -12,9 +12,11 @@ capybara-*.html
 rerun.txt
 pickle-email-*.html
 
-# TODO Comment out these rules if you are OK with secrets being uploaded to the repo
+# TODO Comment out this rule if you are OK with secrets being uploaded to the repo
 config/initializers/secret_token.rb
-config/secrets.yml
+
+# Only include if you have production secrets in this file, which is no longer a Rails default
+# config/secrets.yml
 
 # dotenv
 # TODO Comment out this rule if environment variables can be committed