Translate library/itertools.po (#950)

* feat: to rst:538

* fix: fix sphinx

* feat: to rst:605

* feat: to rst:956

* Apply suggestions from code review

Co-authored-by: Wei-Hsiang (Matt) Wang <mattwang44@gmail.com>

---------

Co-authored-by: Wei-Hsiang (Matt) Wang <mattwang44@gmail.com>

Author: ken71301