pub fn english_from_source(
file: &str,
source: &str,
) -> Result<BTreeMap<String, String>, Vec<ContentError>>Expand description
Parses and validates the source language’s screen text source (a map
of key to text), whatever the language, attributing errors to file.
Reports every problem found. A key’s places
(english_and_places_from_source) are read and left out.