feat(plugin/add): export config type (#9987)

* feat(plugin/add): export config

* Add changeset for @graphql-codegen/add

* update changeset

* Update polite-dancers-warn.md

---------

Co-authored-by: Laurin Quast <[email protected]>

Author: taro-28

.changeset/polite-dancers-warn.md

@@ -0,0 +1,9 @@
+---
+'@graphql-codegen/add': patch
+---
+
+Export configuration types (e.g. `AddPluginConfig`) from the entry point.
+
+```ts
+import type { AddPluginConfig } from '@graphql-codegen/add'
+```

packages/plugins/other/add/src/index.ts

@@ -2,6 +2,8 @@ import { PluginFunction, Types } from '@graphql-codegen/plugin-helpers';
 import { GraphQLSchema } from 'graphql';
 import { AddPluginConfig, VALID_PLACEMENTS } from './config.js';
 
+export * from './config.js';
+
 export const plugin: PluginFunction<AddPluginConfig> = async (
   schema: GraphQLSchema,
   documents: Types.DocumentFile[],