line-length and file-extensions ignored in config files

[LiamPattinson]

As these options have default values specified in the CLI, lines such as the following always return the default value over those specified in the config file:

fortitude/fortitude/src/check.rs

Lines 696 to 698 in a185b11

	let settings = Settings {
	line_length: args.line_length.unwrap_or(file_settings.line_length),
	};

The following lines are at fault:

fortitude/fortitude/src/cli.rs

Lines 100 to 105 in a185b11

	/// Set the maximum allowable line length.
	#[arg(long, default_value = "100")]
	pub line_length: Option<usize>,
	/// File extensions to check
	#[arg(long, value_delimiter = ',', default_values = FORTRAN_EXTS)]
	pub file_extensions: Option<Vec<String>>,

I think the solution will be to manually state the default values in the doc-comments and fall back on the stated defaults in src/check.rs