Rollup merge of rust-lang#132398 - krtab:add_doc_link, r=Noratrieb

Add a couple of intra-doc links to str

library/core/src/str/mod.rs

@@ -212,14 +212,16 @@ impl str {
         }
     }
 
-    /// Finds the closest `x` not exceeding `index` where `is_char_boundary(x)` is `true`.
+    /// Finds the closest `x` not exceeding `index` where [`is_char_boundary(x)`] is `true`.
     ///
     /// This method can help you truncate a string so that it's still valid UTF-8, but doesn't
     /// exceed a given number of bytes. Note that this is done purely at the character level
     /// and can still visually split graphemes, even though the underlying characters aren't
     /// split. For example, the emoji 🧑‍🔬 (scientist) could be split so that the string only
     /// includes 🧑 (person) instead.
     ///
+    /// [`is_char_boundary(x)`]: Self::is_char_boundary
+    ///
     /// # Examples
     ///
     /// ```
@@ -248,15 +250,15 @@ impl str {
         }
     }
 
-    /// Finds the closest `x` not below `index` where `is_char_boundary(x)` is `true`.
+    /// Finds the closest `x` not below `index` where [`is_char_boundary(x)`] is `true`.
     ///
     /// If `index` is greater than the length of the string, this returns the length of the string.
     ///
     /// This method is the natural complement to [`floor_char_boundary`]. See that method
     /// for more details.
     ///
     /// [`floor_char_boundary`]: str::floor_char_boundary
-    ///
+    /// [`is_char_boundary(x)`]: Self::is_char_boundary
     ///
     /// # Examples
     ///
@@ -2193,7 +2195,7 @@ impl str {
     /// Returns a string slice with the prefix removed.
     ///
     /// If the string starts with the pattern `prefix`, returns the substring after the prefix,
-    /// wrapped in `Some`. Unlike `trim_start_matches`, this method removes the prefix exactly once.
+    /// wrapped in `Some`. Unlike [`trim_start_matches`], this method removes the prefix exactly once.
     ///
     /// If the string does not start with `prefix`, returns `None`.
     ///
@@ -2202,6 +2204,7 @@ impl str {
     ///
     /// [`char`]: prim@char
     /// [pattern]: self::pattern
+    /// [`trim_start_matches`]: Self::trim_start_matches
     ///
     /// # Examples
     ///
@@ -2220,7 +2223,7 @@ impl str {
     /// Returns a string slice with the suffix removed.
     ///
     /// If the string ends with the pattern `suffix`, returns the substring before the suffix,
-    /// wrapped in `Some`.  Unlike `trim_end_matches`, this method removes the suffix exactly once.
+    /// wrapped in `Some`.  Unlike [`trim_end_matches`], this method removes the suffix exactly once.
     ///
     /// If the string does not end with `suffix`, returns `None`.
     ///
@@ -2229,6 +2232,7 @@ impl str {
     ///
     /// [`char`]: prim@char
     /// [pattern]: self::pattern
+    /// [`trim_end_matches`]: Self::trim_end_matches
     ///
     /// # Examples
     ///