Add supported for nested profile arrays

[stackoverfloweth]

mapper.register currently expects either a single profile or an array of profiles.
loadProfiles expects an import where each "thing" is a profile

what if my file structure was

└── src
   └── maps
     ├── string.ts
     ├── number.ts
     └── index.ts

and string.ts and number.ts both exported an array of profiles like

export const numberProfiles = [
   ...
]

we would need to support a utility that flattens those arrays nicely