feat: improves plugin writability

docs/plugins/overview.mdx

@@ -78,6 +78,8 @@ export default config;
 
 Payload Plugins are executed _after_ the incoming config is validated, sanitized, and default options are merged in.
 
+However, after all plugins are executed, the full config with all plugins will be re-sanitized.
+
 ## Simple example
 
 Here is an example for how to automatically add a `lastModifiedBy` field to all Payload collections using a Plugin written in TypeScript.

src/config/build.ts

@@ -10,7 +10,8 @@ export function buildConfig(config: Config): SanitizedConfig {
   const sanitized = sanitize(config);
 
   if (Array.isArray(config.plugins)) {
-    return sanitized.plugins.reduce((configWithPlugins, plugin) => plugin(configWithPlugins), sanitized);
+    const configWithPlugins = sanitized.plugins.reduce((updatedConfig, plugin) => plugin(updatedConfig), sanitized);
+    return sanitize(configWithPlugins);
   }
 
   return sanitized;

src/config/types.ts

@@ -18,7 +18,7 @@ type Email = {
 }
 
 // eslint-disable-next-line no-use-before-define
-type Plugin = (config: SanitizedConfig) => SanitizedConfig;
+type Plugin = (config: Config) => Config;
 
 type GeneratePreviewURLOptions = {
   locale: string