Add Framework for Extending Initial Solution Setup

[dylanyoung-dev]

The base solution is great, but some people might want a solution that initializes with specific options/modules enabled. We should create an extensible way to pull in other repos (with a specific format) based on a configuration that you can specify. So for example, someone could specify that they want the base install, but they also want to install a marketing starter kit, that includes additional modules for Marketing enhancements etc. Or if you wanted to install an instance that includes a specific module that your organization uses in most of it's projects (but not all), you could configure which modules you setup the solution with initially. More details to come.

[dylanyoung-dev]

Would be great if you could use framework to install SxA, or other modules on your environment starting up. Some of this functionality already exists, so we'll see. (This may be another Feature entirely)

But the other side, is being able to create your initial solution to include projects with specialized configuration for say xDb/xConnect, so that it would have special instructions to generate model json files, and publish these to specific locations. These could have specialized yaml build/release definitions as well.. Will need to figure this out :-).