Support cascading/multiple env files option

[np-kyokyo]

I want such option that npm dotenv-cli package have like below

Borrow from npm dotenv-cli package documentation:

Cascading env variables

Some applications load from .env, .env.development, .env.local, and .env.development.local (see #37 for more information). dotenv-cli supports this using the -c flag for just .env and .env.local and -c development for the ones above. The -c flag can be used together with the -e flag. The following example will cascade env files located one folder up in the directory tree (../.env followed by ../.env.local):

dotenv -e ../.env -c

multiple env variables

Multiple .env files can be specified, and will be processed in order:

$ dotenv -e .env3 -e .env4 -- <command with arguments>