fix typo in the getting started docs (Significant-Gravitas#3997)

Co-authored-by: Richard Beales <[email protected]>

docs/setup.md

@@ -23,7 +23,7 @@ Get your OpenAI API key from: [https://platform.openai.com/account/api-keys](htt
 [openai/api limits]: https://platform.openai.com/docs/guides/rate-limits/overview#:~:text=Free%20trial%20users,RPM%0A40%2C000%20TPM
 
 !!! important
-    It's highly recommended that you keep keep track of your API costs on [the Usage page](https://platform.openai.com/account/usage).
+    It's highly recommended that you keep track of your API costs on [the Usage page](https://platform.openai.com/account/usage).
     You can also set limits on how much you spend on [the Usage limits page](https://platform.openai.com/account/billing/limits).
 
 ![For OpenAI API key to work, set up paid account at OpenAI API > Billing](./imgs/openai-api-key-billing-paid-account.png)