message: modify usage
diff: @@ -15,11 +15,15 @@ This plugin extends TypeScript Language Service and provides the following featu
  ## Usage
  +First, confirm that your project has typescript(v2.3.x or later) and graphql.
  +
  +To install this plugin, execute the following:
  +
  ```sh
  npm install ts-graphql-plugin -D
  ```
  -Configure `plugins` section of your tsconfig.json, for example:
  +And configure `plugins` section of your tsconfig.json, for example:
  ```json
  {
  