Touch up Debug example from PR 92322

Author: dtolnay

library/core/src/fmt/mod.rs

@@ -572,16 +572,20 @@ impl Display for Arguments<'_> {
 ///
 /// [`debug_struct`]: Formatter::debug_struct
 ///
-/// For custom cases, it's also possible to implement `Debug` using the [`write!`] macro:
+/// Types that do not wish to use the standard suite of debug representations
+/// provided by the `Formatter` trait (`debug_struct`, `debug_tuple`,
+/// `debut_list`, `debug_set`, `debug_map`) can do something totally custom by
+/// manually writing an arbitrary representation to the `Formatter`.
+///
 /// ```
 /// # use std::fmt;
 /// # struct Point {
 /// #     x: i32,
 /// #     y: i32,
 /// # }
-///
+/// #
 /// impl fmt::Debug for Point {
-///     fn fmt(&self, f: &mut fmt::Formatter <'_>) -> fmt::Result {
+///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         write!(f, "Point [{} {}]", self.x, self.y)
 ///     }
 /// }