[1.8.x] Added translation.override() context manager to docs.
[1.8.x] Added translation.override() context manager to docs.

Backport of cf34ee68f0d70cfbcba40524b5d1086ad94874e1 from master

h4r5h1t/django-hauthy,pquentin/django,h4r5h1t/django-hauthy,pquentin/django,pquentin/django,h4r5h1t/django-hauthy,h4r5h1t/django-hauthy