Fix/prerender arg validation (#1490)

* fix: Adding prerender to list of options for validator

* docs: Adding changeset

* docs: Adding prerender flag to readme

.changeset/tender-insects-explain.md

@@ -0,0 +1,5 @@
+---
+'preact-cli': patch
+---
+
+Adds the 'prerender' argument to the list of arguments to be validated against

README.md

@@ -120,6 +120,7 @@ $ preact build
     --template         Path to custom HTML template
     --preload          Adds preload tags to the document its assets  (default false)
     --analyze          Launch interactive Analyzer to inspect production bundle(s)
+    --prerender        Renders route(s) into generated static HTML  (default true)
     --prerenderUrls    Path to pre-rendered routes config  (default prerender-urls.json)
     --brotli           Adds brotli redirects to the service worker  (default false)
     --inline-css       Adds critical css to the prerendered markup  (default true)

packages/cli/lib/commands/build.js

@@ -55,6 +55,11 @@ const options = [
 		name: '--analyze',
 		description: 'Launch interactive Analyzer to inspect production bundle(s)',
 	},
+	{
+		name: '--prerender',
+		description: 'Renders route(s) into generated static HTML',
+		default: true,
+	},
 	{
 		name: '--prerenderUrls',
 		description: 'Path to pre-rendered routes config',