Updated README note about Picard 3 builds

Author: phw

README.md

@@ -4,9 +4,12 @@ This repository provides daily inofficial binary builds for the latest
 development version of [MusicBrainz Picard](https://github.com/metabrainz/picard).
 
 > [!NOTE]
-> *Currently these builds are for the [Picard 2.x](https://github.com/metabrainz/picard/tree/2.x)
-> branch only. The builds will be updated to Picard 3 (master branch) once the new plugin system
-> is in place. See also [issue #4](https://github.com/phw/picard-daily/issues/4).*
+> *These builds are for the latest development version of MusicBrainz Picard 3. There is
+> not yet a stable release of Picard 3, and some changes are still work-in-progress.
+> Specifically Picard 3 features a completely new plugin system, and plugins written for
+> older versions are not compatible. Several existing plugins have been ported to the
+> new system, but many plugins won't be available. You will need to check whether plugins
+> you rely on are available.*
 
 
 ## Packages