Function check_key_placeholders 

pub fn check_key_placeholders<A: ActionSet>(
    bundle: &Bundle,
    path: &str,
    text: &BTreeMap<String, String>,
) -> Result<(), Vec<ContentError>>

Checks that every placeholder of screen text text, read from path in bundle, can be filled: a capitalized {Name} names a key, so it must be {Cursor} or an action of A, as key_text fills them. A lowercase {name} is a value a screen passes (Ctx::text_with’s args), which no file can know, and passes. Each error names the file, the key’s line and the known actions, with code SH2008 (unknown-name).

Errors

Every placeholder that names no key, each its own error.