Use r&b instead of rhytm and blues

beetsplug/lastgenre/aliases.yaml

@@ -1,7 +1,7 @@
 # Ampersands / Delimiters
 drum and bass:
     - d(rum)?[ &n/]*b(ass)?
-rhythm and blues:
+r&b:
     - r(hythm)?[ &n/]*b(lues)?
 rock and roll:
     - rock[- ‐'&n/]*roll

beetsplug/lastgenre/genres-tree.yaml

@@ -624,7 +624,7 @@
     - turkish pop
     - vispop
     - wonky pop
-- rhythm and blues:
+- r&b:
     - funk:
         - deep funk
         - go-go

beetsplug/lastgenre/genres.txt

@@ -1265,8 +1265,7 @@ renaissance music
 requiem
 rhapsody
 rhyming spiritual
-rhythm & blues
-rhythm and blues
+r&b
 ricercar
 riot grrrl
 rock

test/plugins/test_lastgenre.py

@@ -1039,8 +1039,8 @@ class TestAliases:
         [
             ("dnb", "drum and bass"),
             ("drum n bass", "drum and bass"),
-            ("r&b", "rhythm and blues"),
-            ("rnb", "rhythm and blues"),
+            ("r&b", "r&b"),
+            ("rnb", "r&b"),
             ("rock & roll", "rock and roll"),
             ("rock'n'roll", "rock and roll"),
             ("kpop", "k-pop"),