Update stringify-entities

Author: wooorm

package.json

@@ -30,7 +30,7 @@
   "dependencies": {
     "@types/xast": "^1.0.0",
     "ccount": "^1.0.0",
-    "stringify-entities": "^2.0.0"
+    "stringify-entities": "^3.0.0"
   },
   "devDependencies": {
     "browserify": "^16.0.0",