GraphQL Code Generator Add

A plugin for GraphQL Code Generator that adds custom content to generated output files. It is part of the GraphQL Code Generator ecosystem (v0.18.x, now legacy; replaced by v2+ with `@graphql-codegen/add`). This plugin appends or prepends arbitrary code snippets to generated files, useful for adding imports, utilities, or type extensions. It is often used in conjunction with other plugins to enhance generated TypeScript typings for client and server sides. The package is in maintenance mode; users should migrate to the v2 package (`@graphql-codegen/add`).