Change to require React 18

React 16 *may* currently still work depending on your bundler.
But it doesn’t work in Node, because the React team uses an incorrect
export map to expose their JSX runtime in 16 (and 17).

package.json

@@ -78,20 +78,18 @@
   ],
   "dependencies": {
     "@types/hast": "^3.0.0",
-    "@types/prop-types": "^15.0.0",
     "devlop": "^1.0.0",
     "hast-util-to-jsx-runtime": "^2.0.0",
     "mdast-util-to-hast": "^13.0.0",
-    "prop-types": "^15.0.0",
     "remark-parse": "^11.0.0",
     "remark-rehype": "^11.0.0",
     "unified": "^11.0.0",
     "unist-util-visit": "^5.0.0",
     "vfile": "^6.0.0"
   },
   "peerDependencies": {
-    "@types/react": ">=16",
-    "react": ">=16"
+    "@types/react": ">=18",
+    "react": ">=18"
   },
   "devDependencies": {
     "@types/node": "^20.0.0",