Don't always name the `slog.Any()` of type `error` to `"err`"

[bartekpacia]

For example:

logger.Debug("failed to load config file", slog.Any("the_error", err))

Using default TextHandler from slog the output it:

DEBUG msg="failed to load config file" the_error="open /etc/fhomed/config.toml: no such file or directory"

but using this package the output is:

DBG failed to load config file err="open /etc/fhomed/config.toml: no such file or directory"

I'd like to see the_error instead of err.

Thanks for the package! I like it :)