docs: revise docs to provide more detail

README.md

@@ -8,12 +8,56 @@
 
 > Check out the [Online Sandbox](https://gumball12.github.io/google-spreadsheet-dts/)!
 
-This library automatically generates TypeScript types (`*.d.ts`) by parsing Google Sheets.
+This library **automatically generates TypeScript types (`*.d.ts`) by parsing Google Sheets**. It is useful for event tracking systems(like Mixpanel and Google Analytics) or managing internationalized(I18N) data in Google Sheets. Here's an example:
+
+Google Sheet:
+
+| Key                           | Property           | Type                           |
+| ----------------------------- | ------------------ | ------------------------------ |
+| click_conversation_data       | conversation_id    | string                         |
+|                               | created_at         | Date                           |
+|                               | agent_type         | string                         |
+|                               | status             | StatusEnum                     |
+|                               | generate_position  | 'conversation' \| 'playground' |
+| click_message_feedback_button | conversation_id    | string                         |
+|                               | message_id         | string                         |
+|                               | generated_position | 'conversation' \| 'playground' |
+
+Generated TypeScript types:
+
+```ts
+// GoogleSheets.d.ts
+
+// Generated by google-spreadsheet-dts
+/* eslint-disable */
+/* prettier-ignore */
+// @ts-nocheck
+// noinspection JSUnusedGlobalSymbols
+import { StatusEnum } from './StatusEnum';
+export {};
+declare global {
+  export interface GoogleSheets {
+    click_conversation_data: {
+      conversation_id: string;
+      created_at: Date;
+      agent_type: string;
+      status: StatusEnum;
+      generate_position: 'conversation' | 'playground';
+    };
+    click_message_feedback_button: {
+      conversation_id: string;
+      message_id: string;
+      generated_position: 'conversation' | 'playground';
+    };
+  }
+}
+```
 
 ## 💫 Features
 
 - [Parser presets](./src/parser) and Generate types(`*.d.ts`) for **public and private Google Sheets**
-- Customize the type and type file name
+- Customizable type and file name
+- Import types from other files
 
 ### Performance
 
@@ -129,10 +173,10 @@ node scripts/generate-google-sheets-dts.js
 
 ### 3. Use generated types
 
-The above command generates the src/GoogleSheets.ts file as follows:
+The above command generates the src/GoogleSheets.d.ts file as follows:
 
 ```ts
-// src/GoogleSheets.ts
+// src/GoogleSheets.d.ts
 
 // Generated by google-spreadsheet-dts
 /* eslint-disable */