DOC: add release note about revert for 1.0.5
Whatsnew for https://github.com/pandas-dev/pandas/pull/34632

cc @simonjayhawkins @alimcmaster1 
LGTM - thanks for doing this @jorisvandenbossche - I haven’t had a chance to! @alimcmaster1 yes, that's what the whatsnew is supposed to say. But my wording might be confusing? > @alimcmaster1 yes, that's what the whatsnew is supposed to say. But my wording might be confusing? 

Apols I misread - makes sense!