NEWS: Mention FutureBackend API [ci skip]

HenrikBengtsson · HenrikBengtsson · commit 522f670e993e · 2025-03-09T22:50:49.000-07:00
diff --git a/NEWS.md b/NEWS.md
@@ -7,6 +7,8 @@
    `parallelly::availableCores()` or set by the future
    `plan()`. Previously, this had to be implemented by each backend,
    but now it's handled automatically by the future framework.
+   
+ * Add new FutureBackend API for writing future backends.
 
 ## Documentation
 
