refactor(secrets): require ignored .env

[theRemix]

• display helpful message for initial projects
• clear out all secrets in .env.example

related to #1210

Error message

if the user does not create a .env file, the following message is displayed and the process exits.

❗You probably forgot to create a '.env' file.❗
      Copy .env.example to .env

[YasharF]

The current .env setup is by design.