Add missing dev-dependencies

Author: wooorm

package.json

@@ -44,12 +44,14 @@
     "c8": "^7.0.0",
     "hastscript": "^7.0.0",
     "prettier": "^2.0.0",
+    "rehype-parse": "^8.0.3",
     "remark-cli": "^10.0.0",
     "remark-preset-wooorm": "^9.0.0",
     "rimraf": "^3.0.0",
     "tape": "^5.0.0",
     "type-coverage": "^2.0.0",
     "typescript": "^4.0.0",
+    "unified": "^10.1.0",
     "xo": "^0.44.0"
   },
   "scripts": {