Small enhancement to description of From trait

- fix small typo
- avoid repetition of formulations

Author: jonaspleyer

library/core/src/convert/mod.rs

@@ -466,9 +466,9 @@ pub trait Into<T>: Sized {
 /// Prefer using [`Into`] over using `From` when specifying trait bounds on a generic function.
 /// This way, types that directly implement [`Into`] can be used as arguments as well.
 ///
-/// The `From` is also very useful when performing error handling. When constructing a function
+/// The `From` trait is also very useful when performing error handling. When constructing a function
 /// that is capable of failing, the return type will generally be of the form `Result<T, E>`.
-/// The `From` trait simplifies error handling by allowing a function to return a single error type
+/// It simplifies error handling by allowing a function to return a single error type
 /// that encapsulate multiple error types. See the "Examples" section and [the book][book] for more
 /// details.
 ///