Update metaschema

Author: effigies

src/metaschema.json

@@ -359,6 +359,18 @@
                   },
                   "additionalProperties": false
                 },
+                "modality_agnostic": {
+                  "type": "object",
+                  "patternProperties": {
+                    "^[a-zA-Z0-9_]+$": {
+                      "anyOf": [
+                        { "$ref": "#/definitions/pathRule" },
+                        { "$ref": "#/definitions/stemRule" }
+                      ]
+                    }
+                  },
+                  "additionalProperties": false
+                },
                 "tables": {
                   "type": "object",
                   "patternProperties": {
@@ -372,7 +384,7 @@
                   "additionalProperties": false
                 }
               },
-              "required": ["core", "tables"],
+              "required": ["core", "modality_agnostic", "tables"],
               "additionalProperties": false
             },
             "deriv": {