Easy Setup Update

Added a way to check the .env file on start and look for FLAG=#src. If it is found, it'll set up the .env file for you and generate credentials for SALT and PASS, as well as remove the FLAG from the .env file so it won't remake credentials each time passgen is ran.

And in the very odd chance that you would like new .env credentials, all you will need to do is add FLAG=#src back to the .env file and then run passgen.py again.