1.To parse a TOML configuration file into a Rust struct with the toml crate, what must the config struct derive?
2.What does the .ok() do in the call dotenvy::dotenv().ok();?
3.In the recommended pattern, what is the relationship between dotenvy::dotenv() and std::env::var("KEY")?
4.Given the taught expression toml::from_str(&fs::read_to_string(path)?)?, why are there two ? operators?
5.According to the module, what is the idiomatic way to combine TOML files and environment variables for configuration?
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