New Stable Branch for Krita docs

[Wolthera]

Hi,

We've just finished with documenting the changes for Krita 5.2, and
made a new branch (krita/5.2) accordingly. I've made a sysadmin ticket
to move the docs.krita.org website builder to use this new branch, and
am writing this e-mail to request switching scripty to get POTs from
the new branch.

Thanks in advance,
-- 
Wolthera

PS, if you before had issues with the 'LOGO_URL' variable when testing
translations for the 5.1 branch, that should be fixed in this new
branch.