Consider using local, per-widget configuration files

Parade is currently configured using a single configuration file. This configuration object can get complex, and issues are open to potentially expand the support configuration schema. For reference, the current widgets Parade configuration is **over 2100 lines long** for 68 widgets.

It would be nice to support local configuration files using a `.example.ts` suffix, similarly to how test files use an auto-detected `.spec.ts` extension. This would reduce the size of the global configuration file (which may still be required for settings that are actually global), would increase maintainability, and would be symmetrical with how we currently handle testing.