Changing env variables to flags

[NicksPatties]

It's difficult to remember what environment variables I should use if I want to change the exercises directory or location of the sweet database. I don't know which method would be the easiest for users to understand.

Method 1: environment variables (current)

todo: fill pros and cons of this method

Method 2: command flags

todo: fill pros and cons of this method

[NicksPatties]

Perhaps something like sweet env like go env would be useful, too. Or use a configuration file. I like this model of managing configuration, so something similar that prioritizes (in order):

• cli flags
• environment variables
• configuration files
• built-in configuration