Added docs for Baggy.hash

Author: Jan-Olof Hendig

doc/Type/Baggy.pod6

@@ -275,6 +275,20 @@ Returns zero.
     my $breakfast = bag <eggs bacon>;
     say $breakfast.default;                           # 0
 
+=head2 method hash
+
+Defined as:
+
+    method hash(Baggy:D:) returns Hash:D
+
+Returns a L<Hash|/type/Hash> where the elements of the invocant
+are the keys and their respective weights the values;
+
+    my $breakfast = bag <eggs bacon bacon>;
+    my $h = $breakfast.hash;
+    say $h.WHAT;                                      # (Hash)
+    say $h;                                           # {bacon => 2, eggs => 1}
+
 =head2 method Bool
 
 Defined as: