update readme with relevant tip

docs/getting-started/introduction.mdx

@@ -1,12 +1,12 @@
 ---
 title: Introduction
-description: 'The open-source language model computer.'
+description: "The open-source language model computer."
 ---
 
 <img
   src="https://www.openinterpreter.com/OI-O1-BannerDemo-3.jpg"
   alt="thumbnail"
-  style={{ transform: 'translateY(-1.25rem)' }}
+  style={{ transform: "translateY(-1.25rem)" }}
 />
 
 The 01 project is an open-source ecosystem for artificially intelligent devices.
@@ -41,4 +41,10 @@ poetry install
 poetry run 01
 ```
 
+You will need an Open AI API key or you will have to run 01 with the --local option
+
+```bash
+poetry run 01 --local
+```
+
 _Disclaimer:_ The current version of 01OS is a developer preview