Errors in config file don't point to correct span

[triallax]

To reproduce, write this to your config file:

intro-banner = "short"
promtp = "numbat> "
#   ^^ see the typo here

then run numbat, which will error with this output:

Error while loading /home/triallax/.config/numbat/config.toml: TOML parse error at line 1, column 1
  |
1 | intro-banner = "short"
  | ^^^^^^^^^^^^^^^^^^^^^^
unknown field `promtp`

[sharkdp]

Thank you for reporting this. This seems to be an upstream error: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=b2368bcdc7aff8aac38ed6ad1ace920b

[sharkdp]

Yes. See:

toml-rs/toml#593
toml-rs/toml#589

[sharkdp]

The issue seems to be related to serde's flatten feature. So if we move the MainConfig into the Config struct, that issue might be fixed. I think this would be a viable solution for us. It's not like our config needs that type of granularity right now.