feat: added config file support

[Dionid]

Added support for using config file.

File can be like this:

# /config.yaml

verbose: true
schema: public
out: ./somewhere
exclude:
  - user

And using will be like:

xo --config ./config.yaml schema "postgres://postgres:postgres@localhost:5441/db"

If you like this, i will complete config file with all supported cli flags.