[DOC] Tweaks for String#delete_suffix! (ruby#13872)

Author: BurdetteLamar

doc/string.rb

@@ -428,6 +428,7 @@
 # - #squeeze!: Removes contiguous duplicate characters; returns +self+.
 # - #delete!: Removes characters as determined by the intersection of substring arguments.
 # - #delete_prefix!: Removes leading prefix; returns +self+ if any changes, +nil+ otherwise.
+# - #delete_suffix!: Removes trailing suffix; returns +self+ if any changes, +nil+ otherwise.
 # - #lstrip!: Removes leading whitespace; returns +self+ if any changes, +nil+ otherwise.
 # - #rstrip!: Removes trailing whitespace; returns +self+ if any changes, +nil+ otherwise.
 # - #strip!: Removes leading and trailing whitespace; returns +self+ if any changes, +nil+ otherwise.

string.c

@@ -11376,9 +11376,10 @@ deleted_suffix_length(VALUE str, VALUE suffix)
  *  call-seq:
  *    delete_suffix!(suffix) -> self or nil
  *
- *  Like String#delete_suffix, except that +self+ is modified in place.
- *  Returns +self+ if the suffix is removed, +nil+ otherwise.
+ *  Like String#delete_suffix, except that +self+ is modified in place;
+ *  returns +self+ if the suffix is removed, +nil+ otherwise.
  *
+ *  Related: see {Modifying}[rdoc-ref:String@Modifying].
  */
 
 static VALUE