bpo-42960: Add resource.RLIMIT_KQUEUES constant from FreeBSD (GH-24251)

diff --git a/Doc/library/resource.rst b/Doc/library/resource.rst
index e4eac43..00ff3b5 100644
--- a/Doc/library/resource.rst
+++ b/Doc/library/resource.rst
@@ -255,6 +255,14 @@
 
    .. versionadded:: 3.4
 
+.. data:: RLIMIT_KQUEUES
+
+   The maximum number of kqueues this user id is allowed to create.
+
+   .. availability:: FreeBSD 11 or later.
+
+   .. versionadded:: 3.10
+
 Resource Usage
 --------------