G.CMT.03 Use spaces in document comments instead of tabs

[Level] Suggestion

[Description]

Rust code style promotes the use of four spaces instead of tabs, and four spaces should be used consistently in the documentation comments.

[Bad Case]

Tab is used in the following document comments.

#![allow(unused)]
fn main() {
// Bad：Tab indentation is used in document comments
///
/// Struct to hold two strings:
/// 	- first		one
/// 	- second	one
pub struct DoubleString {
   ///
   /// 	- First String:
   /// 		- needs to be inside here
   first_string: String,
   ///
   /// 	- Second String:
   /// 		- needs to be inside here
   second_string: String,
}
}

[Good Case]

#![allow(unused)]
fn main() {
// Good：Four spaces indentation is used in document comments
///
/// Struct to hold two strings:
///     - first        one
///     - second    one
pub struct DoubleString {
   ///
   ///     - First String:
   ///         - needs to be inside here
   first_string: String,
   ///
   ///     - Second String:
   ///         - needs to be inside here
   second_string: String,
}
}

[Lint detect]