Improve "write the first review" text
Summary: The current text is ambiguous and un-exciting. This patches makes it clear and enticing! Who doesn't want to be the first to do something?
Test Plan:
Reviewers: Discover Software Store, apol
Reviewed By: Discover Software Store, apol
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D10476