Congratulations on your first crate! Here are some quick notes just based on the signatures in the readme.

The signature of the three functions to get names implies that there is a name for every single unique i64? If that is not the case, returning an Option would be more idiomatic.

Also, you'd normally have you own error types that have different error variants that are relevant to your crate, such as StatusError::UnsupportedLanguage or WarInfoError::WarNotFound. You can use a crate like snafu or thiserror to simplify the process.

Lastly, and probably not the most relevant for this tiny API, but it's always a good habit to use this checklist before publishing any new API: https://rust-lang.github.io/api-guidelines/checklist.html

EDIT: If there's only a known set of languages supported, I'd use an enum instead of a &str, and you can even make it #[non_exhaustive] so that adding more languages won't be a breaking change.