feat: add google auth demo

demos/demo-google-auth.ts

+import dotenv from 'dotenv-safe'
+import { oraPromise } from 'ora'
+
+import { ChatGPTAPIBrowser } from '../src'
+
+dotenv.config()
+
+/**
+ * Demo CLI for testing basic functionality using Google auth.
+ *
+ * ```
+ * npx tsx demos/demo.ts
+ * ```
+ */
+async function main() {
+  const email = process.env.OPENAI_EMAIL
+  const password = process.env.OPENAI_PASSWORD
+
+  const api = new ChatGPTAPIBrowser({
+    email,
+    password,
+    isGoogleLogin: true,
+    debug: false,
+    minimize: true
+  })
+  await api.initSession()
+
+  const prompt =
+    'Write a python version of bubble sort. Do not include example usage.'
+
+  const res = await oraPromise(api.sendMessage(prompt), {
+    text: prompt
+  })
+  console.log(res.response)
+
+  // close the browser at the end
+  await api.closeSession()
+}
+
+main().catch((err) => {
+  console.error(err)
+  process.exit(1)
+})