Backport PR #57029 on branch 2.2.x (DOC: Add DataFrame.to_numpy method) (#57940)

Backport PR #57029: DOC: Add `DataFrame.to_numpy` method

Co-authored-by: Zhengbo Wang <[email protected]>

Author: meeseeksmachine

doc/source/reference/frame.rst

@@ -49,6 +49,7 @@ Conversion
    DataFrame.infer_objects
    DataFrame.copy
    DataFrame.bool
+   DataFrame.to_numpy
 
 Indexing, iteration
 ~~~~~~~~~~~~~~~~~~~