Consider supporting dotfiles

[teijo]

Reading ".env" files is very close to what the library is doing already. The API could be expanded to parsing also these files with e.g. const result = requireEnvironmentFile(filePath: string).

dotenv package as a reference: https://github.com/motdotla/dotenv

[teijo]

Hmm, scratch that?

User should probably just use the env file loader and then use this library to validate the result of merged config file and environment variables. dotenv just populates process.env, which would then be read by process-env-parser.