add enumutils.items for sparse enums, typetraits.SomeSparseEnum (#17080)

* add enumutils.items for enum with holes
* changelog
* ref in lib.rst
* use `type SomeSparseEnum* = (not Ordinal) and enum` instead of concept
* address comment: rename back to enum with holes

1 files changed, 3 insertions, 0 deletions

diff --git a/doc/lib.rst b/doc/lib.rst
index 11b479902..47ede70ee 100644
--- a/doc/lib.rst
+++ b/doc/lib.rst
@@ -85,6 +85,9 @@ Algorithms
 * `algorithm <algorithm.html>`_
   This module implements some common generic algorithms like sort or binary search.
 
+* `std/enumutils <enumutils.html>`_
+  This module adds functionality for the built-in ``enum`` type.
+
 * `sequtils <sequtils.html>`_
   This module implements operations for the built-in ``seq`` type
   which were inspired by functional programming languages.