docs: expand requireConfig (#9973)

docs/usage/self-hosted-configuration.md

@@ -331,6 +331,8 @@ Warning: this is an experimental feature and may be modified or removed in a fut
 
 ## requireConfig
 
+If this is set to `false`, it means that Renovate won't require a config file such as `renovate.json` to be present in each repository and will run even if one is missing.
+
 ## secrets
 
 Secrets may be configured by a bot admin in `config.js`, which will then make them available for templating within repository configs.

lib/config/definitions.ts

@@ -351,7 +351,8 @@ const options: RenovateOptions[] = [
   },
   {
     name: 'requireConfig',
-    description: 'Set to true if repositories must have a config to activate.',
+    description:
+      'Set to false if it is optional for repositories to contain a config.',
     stage: 'repository',
     type: 'boolean',
     default: true,