chore: add sample env file

Signed-off-by: SphericalKat <amolele@gmail.com>

sample.env

@@ -0,0 +1,5 @@
+DATABASE_URL='<insert db url here>'
+SECRET_KEY_BASE='<insert secret key here>'
+SWOOSH_USERNAME='noreply@katb.in'
+SWOOSH_PASSWORD='<insert your password here>'
+SWOOSH_SMTP_RELAY='smtp.example.com'