Mention how to install uniffi-bindgen if we fail to execute it.

[mhammond]

Also updates other instructions to reflect the name is uniffi_bindgen
rather than uniffi-bindgen.

[rfk]

r+, but also, I wonder if we should change the crate name so that it is in fact the more idiomatic uniffi-bindgen...

[mhammond]

I wonder if we should change the crate name so that it is in fact the more idiomatic uniffi-bindgen...

I assumed that situation was forced on us - +1 to unifiiing that if possible 🥴

[rfk]

Oh no, it looks like hyphens-versus-underscores is a whole thing and now that I've published with the underscore, we might not be able to use the hyphen.

For example, linking to the crate as uniffi-bindgen works as far as crates.io is concerned, but attempting to cargo install uniffi-bindgen fails as you note above. Bleh.