specify minimum npm version

docs/index.md

@@ -6,7 +6,7 @@ Quartz is a fast, batteries-included static-site generator that transforms Markd
 
 ## 🪴 Get Started
 
-Quartz requires **at least [Node](https://nodejs.org/) v18.14** to function correctly. Ensure you have this installed on your machine before continuing.
+Quartz requires **at least [Node](https://nodejs.org/) v18.14** and `npm` v9.3.1 to function correctly. Ensure you have this installed on your machine before continuing.
 
 Then, in your terminal of choice, enter the following commands line by line:
 

package.json

@@ -19,6 +19,7 @@
     "profile": "0x -D prof ./quartz/bootstrap-cli.mjs build --concurrency=1"
   },
   "engines": {
+    "npm": ">=9.3.1",
     "node": ">=18.14"
   },
   "keywords": [