Soft Feature Freeze

[David Edmundson]

Just to clarify all of this:

>From now on 5.23 branch is forked.
Master is open to any new changes, new features and new strings and
can depend on new frameworks.

The 5.23 branch is open to bug fixes only, but doing these bugfixes is
actively encouraged!
They should be committed on master and backported. The period between
5.22.90 and 5.23.0 is treated exactly the same as the stable release
cycle that happens throughout the rest of Plasma/5.23.

David