CodegenCLI - Improve first experience defaults

[calvincestari]

This is trying to improve the first experience wit codegen based on what are the common issues being experienced since the release of 1.0.0.

1. Require moduleType as input on init
   a. embeddedInTarget require target name
2. Operation changed to inSchemaModule
3. Documentation changes needed
   a. Everywhere we link to init command should be updated
   b. Expand details on module type and what is required to be done by them, i.e.: other would require a podspec to be created.

[calvincestari]

Possibly related to #2594