🚀 [Docs] Show the default config values

[izelnakri]

Hi there, first of all thanks for this awesome package. Documentation is also well thought after, sectioned and easy to read.

However I had a major problem in terms of DX: I'm not sure what is the default configuration(~/.config/delta/config.yml) delta uses.

Each config key is well described but I don't know what value is the default without checking each one out manually: I would like to have this default config object values shown in the documentation so I can save significant time learning this tool and ease my own configuration(if I need to configure certain thing).

Without this declaration, delta results in too much time for setting it up for the first time and eventually, making sure whether an old config is not out-of-date with the current existing default configuration.

Also I tried to see if someone else created a similar issue, and couldn't find the specific issue there were many results. Would appreciate if we can have this on: https://dandavison.github.io/delta/configuration.html

Thanks again for all the good work!