Milestone for 5.1 created

[Wolthera]

Hey everyone,

With the impending string freeze, I went ahead and made the milestone for 5.1:
https://invent.kde.org/graphics/krita/-/milestones/3

Please tag your MRs that will contain fancy new features that
definitely break string freeze with this new milestone.

MRs that fix bugs should be marked with 5.0:
https://invent.kde.org/graphics/krita/-/milestones/2#tab-merge-requests

-- 
Wolthera