Hello all!
First of all, thanks for this awesome tool which I love every day.
In very humble opinion there are two features that are missing:

External configuration file

Rather than storing all options in .gitconfig, can we store the configuration inside an external file and just reference that from the .gitconfig?

Like:

# .gitconfig
[delta]
  config = /path/to/config

and

delta --config=/path/to/config

I don't have any preference for the config format, it might be the same gitconfig format, TOML or YAML.

Support multiple profiles

Following the proposal above (but given we use environment variable it is technically independent of it), we might add a profile option which specifies which section to load. For instance:

# .gitconfig

[delta]
  config = /path/to/config
  profile = main

and

delta --config=/path/to/config --profile=main

will look for section delta.main rather than simply delta.

What do you think about it?