Documentation Catalan images

Summary: First Catalan images for Krita User Manual

Test Plan: Commit it, and tomorrow I modify related link

Reviewers: VDG, woltherav, Krita: Manual

Reviewed By: woltherav, Krita: Manual

Subscribers: woltherav

Tags: Krita: Manual

Differential Revision: https://phabricator.kde.org/D20446