Allow Configurable Option to Change Default Cookbook Generation policy_mode

Describe the Enhancement:

I would like to have a local setting that I can set, similar to chefdk.generator.license, that allows me to change the default behavior of the cookbook generator to generate berks cookbooks by default. Maybe something like chefdk.generator.policy_mode false

Describe the Need:

Anyone that regularly generates cookbooks with pipelines or development process that are tied to using Berksfile cookbooks would like a tunable parameter that they can set on their development workstation to default to this cookbook style.

Current Alternative

When generating each cookbook, you can specify -b or --berks flags. This isn't ideal as there is one more step that we could forget or forget to inform someone we're helping learn our cookbook development processes.

Can We Help You Implement This?:

Submitting open source code is, unfortunately, difficult at my current place of employment.

Start by locating the configuration handling for chefdk.generator.license and the cookbook generator entry point that processes -b or --berks. Done means a local setting changes the default cookbook policy mode while the explicit command-line flags continue to work.