Make (at least some) cookbooks standalone

[brohitbrose]

Currently, if a user wants to start a project based on one of the cookbooks, they have to manually tweak/merge .gradle files on their own and copy-paste wrappers -- at minimum.

This is not a problem for the original use case behind the cookbooks (primarily running without changes, or only making changes in a sandboxed, throwaway environment). reference-type cookbooks could remain this way (though it may not hurt per-se to let these be standalone too). But for how-to guides, we should absolutely offer a quick, simple path where developers can select them as a starting point for their own project.

UPDATE: discussed with ajay-gov, will defer for now. We may utilize a git sparse-checkout type solution combined with swim-create.