Whatsnew for float-to-top (#5714)

* Use isort's float-to-top

* .

* whatsnew for float-to-top

Author: max-sixty

doc/whats-new.rst

@@ -55,6 +55,8 @@ Internal Changes
   By `Benoit Bovy <https://github.com/benbovy>`_.
 - Improve the performance of reprs for large datasets or dataarrays. (:pull:`5661`)
   By `Jimmy Westling <https://github.com/illviljan>`_.
+- Use isort's `float_to_top` config. (:pull:`5695`).
+  By `Maximilian Roos <https://github.com/max-sixty>`_.
 
 .. _whats-new.0.19.0: