[Keyboard] Add community layout support to Piantor (#19455)

keyboards/beekeeb/piantor/info.json

@@ -22,6 +22,7 @@
     "split": {
         "enabled": true
     },
+    "community_layouts": ["split_3x6_3"],
     "layouts": {
         "LAYOUT_split_3x6_3": {
             "layout": [