Add main entry point exposing `/lightning` directory

• Add an lightning_adapter.js
• Allow specifying a config file
• Move what can be configurable to the base config file
• Add main in package.json
• Expose services
• Refactor the server to use the adapter

I will submit a PR in a few.

[alexbosworth]

I need to document it a bit better but what you need to do is to do $ base64 admin.macaroon and base64 tls.cert in order to get the appropriate values for lightning_daemon.js

[plwalters]

Disregard I see what you mean it falls back in server mode to the env variables