Update README.md (#380)

* Update README.md

If we will remove new_sets, then we should deprecate it instead of sets.

* Update README.md

---------

Co-authored-by: Ivo List <ilist@google.com>
diff --git a/README.md b/README.md
index b72b729..fd2e275 100644
--- a/README.md
+++ b/README.md
@@ -47,9 +47,8 @@
 * [partial](docs/partial_doc.md)
 * [paths](docs/paths_doc.md)
 * [selects](docs/selects_doc.md)
-* [sets](lib/sets.bzl) - _deprecated_, use `new_sets`
+* [sets](docs/new_sets_doc.md)
 * [modules](docs/modules_doc.md)
-* [new_sets](docs/new_sets_doc.md)
 * [shell](docs/shell_doc.md)
 * [structs](docs/structs_doc.md)
 * [subpackages](docs/subpackages_doc.md)