Allow flags for dce init

[nathanagood]

Is your feature request related to a problem? Please describe.

The dce init command only works by prompting a user for the API URL and other information. Anything that is required should be able to be provided on the command line so dce init can be called in scripts.

Describe the solution you'd like

Something like dce init --api-url https://api.example.com. Basepath should be able to be provided but should just default to 'api', which will be the case for anyone except advanced users.

Describe alternatives you've considered

Using cat to write the config file works, but that could change at any time since it's not really documented behavior, nor is the format of the configuration file documented because while it's there editing the file outside the use of the CLI isn't particularly encouraged.

Additional context