Final update to release notes

Author: whaeck

ReleaseNotes.md

@@ -1,7 +1,7 @@
 # Release Notes—tools
 Given here are some release notes for tools.
 
-## [tools v0.4.0](https://github.com/njoy/tools/pull/xxx)
+## [tools v0.4.0](https://github.com/njoy/tools/pull/44)
 New features:
   - added a partial implementation of the C++23 ranges standard: chunk_view, chunk_by_view, stride_view and repeat_view (LLVM implementations for these views were used as models for our C++17 based implementations)
   - updates to drop_view, values_view, keys_view and take _view