Check `description` field in `Cargo.toml` for typos

[lopopolo]

Is your feature request related to a particular use-case?

I published a crate to crates.io with a typo in the description field in Cargo.toml.

Describe the solution you'd like to implement/see implemented

Perform spellchecking on the description field in Cargo.toml.

Describe alternatives you've considered

code review, post-publish review.

Additional context

[drahnr]

There is only a small chunk of code missing to make this functional, adding another match arm to handle ChevkEntity::ManifestDesctiption in https://github.com/drahnr/cargo-spellcheck/blob/748b4f0bcec477695eb7ade98a01f03634efe277/src/traverse/mod.rs#L555

I'd be very happy to review a PR for this 😊

[lopopolo]

Thanks for the pointer @drahnr.

I put up a WIP PR here:

• https://github.com/drahnr/cargo-spellcheck/pull/235