chore: add node v20 suggestions

Author: jescalada

package.json

@@ -142,5 +142,8 @@
       "last 1 firefox version",
       "last 1 safari version"
     ]
+  },
+  "engines": {
+    "node": ">=20.19.2" 
   }
 }

website/docs/development/contributing.mdx

@@ -7,7 +7,7 @@ Here's how to get setup for contributing to GitProxy.
 ## Setup
 The GitProxy project relies on the following pre-requisites:
 
-- [Node](https://nodejs.org/en/download) (22+)
+- [Node](https://nodejs.org/en/download) (20+)
 - [npm](https://npmjs.com/) (8+)
 - [git](https://git-scm.com/downloads) or equivalent Git client. It must support HTTP/S.