Suggestion: Add service and adapter to koa-ts

[osirisguitar]

Add a service with:

src/
serviceName/
index.ts
types.ts
adapters/
postgresAdapter/
index.ts

Also make api.ts import the routes related to the service from serviceName/index.ts instead of being declared in api.ts itself.

My suggestion is to put adapter under service instead of under src/adapters to prepare for a future extraction of serviceName to a separate micro service (all dependencies under service).