Fix typo: "two things" → "three things" (#10)

The list actually contains three items, not two.

Author: Chesars

docs/index.md

@@ -46,7 +46,7 @@ while True:
     Different LM APIs may have slightly different conventions for how to structure these messages.
 
 
-So to get this to work, we only need to implement two things:
+So to get this to work, we only need to implement three things:
 
 1. Querying the LM API (this can get annoying if you want to support all LMs, or want detailed cost information, but is very simple if you already know which model you want)
 2. Parsing the action (`parse_action`). You don't need this if you use the tool calling functionality of your LM if it supports it, but this is more provider-specific, so we wo'nt cover it in this guide for now (don't worry, the performance should not be impacted by this).