Read MJ_INSTALL_* environment variables and return a partial config.
Only fields with a corresponding env var set are included. Fields without
an env var are omitted (not set to undefined), so they won't override
values from earlier layers in the config chain.
Read
MJ_INSTALL_*environment variables and return a partial config.Only fields with a corresponding env var set are included. Fields without an env var are omitted (not set to
undefined), so they won't override values from earlier layers in the config chain.