Issues with deployment on vercel platform

[finfin]

There are two issues when I try to deploy on vercel,

1. Vercel defaults to node v22, but serverless function did not support v22, need to change the node version.

[17:13:25.719] 09:13:25 [build] Rearranging server assets...
[17:13:25.731] 09:13:25 [@astrojs/sitemap] `sitemap-index.xml` created at `.vercel/output/static`
[17:13:25.731] 09:13:25 [WARN] [@astrojs/vercel/serverless] 
[17:13:25.732] 	The local Node.js version (22) is not supported by Vercel Serverless Functions.
[17:13:25.732] 	Your project will use Node.js 18 as the runtime instead.
[17:13:25.732] 	Consider switching your local version to 18.
[17:13:25.732] 
[17:13:25.732] 09:13:25 [@astrojs/vercel/serverless] Bundling function ../../_functions/entry.mjs
[17:13:28.772] 09:13:28 [build] Waiting for integration "@astrojs/vercel/serverless", hook "astro:build:done"...
[17:13:29.792] 09:13:29 [build] Server built in 15.24s
[17:13:29.792] 09:13:29 [build] Complete!
[17:13:29.845] Done in 30.38s.
[17:13:48.666] Build Completed in /vercel/output [2m]
[17:13:49.332] Deploying outputs...
[17:13:49.670] Error: The following Serverless Functions contain an invalid "runtime":
[17:13:49.672]   - _render (nodejs18.x). Learn More: https://vercel.com/guides/serverless-function-contains-invalid-runtime-error
[17:13:50.150] 

solution: add following to package.json will solve this error, reference

"engines": {
    "node": "22.x"
  }

2. Vercel hobby(free) plan only supports up to 12 serverless function, which will show following errors

[17:06:33.644] Deploying outputs...
[17:06:49.568] Error: No more than 12 Serverless Functions can be added to a Deployment on the Hobby plan. Create a team (Pro plan) to deploy more. Learn More: https://vercel.link/function-count-limit
[17:06:50.160] 

possible solution: add some note in readme