Feature Request: A basic SysV style init

[venomdev]

Would it be possible to add a simplified SysV style init function?

You could specify an environment variable like TINI_INIT_RC=3 and it would load any scripts in alphabetical order from rcX.d folders. If the environment variable is not set then this function is skipped.

This should not break any compatibility with the docker built in --init as if/when docker uses the feature it is still turned on or off with an environment variable and not a command switch.