support discarding tags, not just keys

Author: k-yle

schemas/discarded.json

@@ -2,9 +2,12 @@
     "$schema": "http://json-schema.org/draft-07/schema#",
     "$id": "https://github.com/ideditor/schema-builder/raw/main/schemas/discarded.json",
     "title": "Discarded tags",
-    "description": "Keys of tags to be deleted when editing features.",
+    "description": "Keys or tags to be deleted when editing features.",
     "type": "object",
     "additionalProperties": {
-        "type": "boolean"
+      "anyOf": [
+        { "type": "boolean", "enum": [true] },
+        { "type": "object", "additionalProperties": { "type": "boolean", "enum": [true] } }
+      ]
     }
 }