feat(rumdl): update schema to v0.1.65 (SchemaStore#5522)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: rvben

src/schemas/json/rumdl.json

@@ -5,6 +5,10 @@
   "description": "rumdl configuration for linting Markdown files. Rules can be configured individually using [MD###] sections with rule-specific options.",
   "type": "object",
   "properties": {
+    "extends": {
+      "description": "Path to a base config file to inherit settings from.\nSupports relative paths, absolute paths, and `~/` for home directory.\nExample: `extends = \"../base.rumdl.toml\"`",
+      "type": ["string", "null"]
+    },
     "global": {
       "$ref": "#/definitions/GlobalConfig",
       "description": "Global configuration options",