Add metabrainz (#2454)

* Create metabrainz

The MetaBrainz Foundation is a global community creating and maintaining
an open encyclopedia of music and arts metadata.

* category-orgs: include metabrainz

---------

Co-authored-by: nobody <>

data/category-orgs

@@ -6,6 +6,7 @@ include:csis
 include:emojipedia
 include:f-droid
 include:ieee
+include:metabrainz
 include:nist
 include:openstreetmap
 include:paskoocheh

data/metabrainz

@@ -0,0 +1,8 @@
+acousticbrainz.org
+bookbrainz.org
+coverartarchive.org
+critiquebrainz.org
+listenbrainz.org
+messybrainz.org
+metabrainz.org
+musicbrainz.org