Missing 'docs/configfiles.txt' but it remains referenced in documentation

[keithzg]

In docs/commands.rst, it twice mentions what sounds like a very helpful file, docs/configfiles.txt:

The value for this option describes the source of MediaWiki articles and images for the command and can be of one of the following types:
...
This value for --config corresponds to type=mwapi in a configuration file (see docs/configfiles.txt),
...

• A filename of a configuration file (see docs/configfiles.txt).

However, there appears to be no configfiles.txt in the docs folder. A quick gander at the revision history through the tags shows that it was removed before version 0.13. Where now, then, is the documentation on writing a config file and the options available? Surely the existing text referring to docs/configfiles.txt should be updated to wherever that information is now, right? I see that 554d0de removed configfiles.txt, but there would still seem to be a need for such documentation of configuration files since for instance mw-zip reports

mw-zip --help
Usage: mw-zip [OPTIONS] [ARTICLETITLE...]

Options:
  -h, --help            show this help message and exit
  -c CONFIG, --config=CONFIG
                        configuration file, ZIP file or base URL
...

so configuration files are presumably still supported...