Document $*0, etc.

Closes #4538

Author: coke

doc/Language/REPL.rakudoc

@@ -10,6 +10,29 @@ The C<REPL> is an interactive Raku prompt. Each line of code you enter in the C<
 is executed, and if no output was generated, the value returned
 by the expression is output.
 
+=head1 Previous Values
+
+As you enter commands into the REPL, each line has a numeric ID associated with it, starting
+with C<0>. On subsequent lines, you can use the result with a special variable only available
+in the REPL.  C<$*0>, C<$*1>, etc. In this example, we calculate two values and then use them
+both on the third line.
+
+=begin code :lang<REPL>
+✗ raku
+Welcome to Rakudo™ v2025.08.
+Implementing the Raku® Programming Language v6.d.
+Built on MoarVM version 2025.08.
+
+To exit type 'exit' or '^D'
+[0] > 3+2
+5
+[1] > 7+1
+8
+[2] > $*0 * $*1
+40
+[3] >
+=end code
+
 =head1 Trap
 
 B<Note>: Running code in the C<REPL> is not equivalent to saving the code in a file and

doc/Type/Pair.rakudoc

@@ -217,9 +217,9 @@ For more about format strings, see L<sprintf|/routine/sprintf>.
 
 =head2 method kv
 
-    multi method kv(Pair:D: --> List:D)
+    multi method kv(Pair:D: --> Seq:D)
 
-Returns a two-element L<C<List>|/type/List> with the I<key> and I<value> parts of
+Returns a two-element L<C<Seq>|/type/Seq> with the I<key> and I<value> parts of
 C<Pair>, in that order. This method is a special case of the same-named
 method on L<C<Hash>|/type/Hash>, which returns all its entries as a list of keys and
 values.