Doc: fixed missing behavior explaination of sort=false for groupby issue #47529
- [x] closes #47529 
- [x] All code checks passed

Changes were made by @hubschne and @raanasn at the python conference 2023 Berlin workshop

Reviewer suggestions: @phofl, @noatamir, @jorisvandenbossche and @marcogorelli Thanks @raanasn!