doc: README table of contents has Documentation twice

Signed-off-by: Nick Mitchell <[email protected]>

Author: starpit

README.md

@@ -14,7 +14,7 @@
 
 PDL is a declarative language designed for developers to create reliable, composable LLM prompts and integrate them into software systems. It provides a structured way to specify prompt templates, enforce validation, and compose LLM calls with traditional rule-based systems.
 
-[**Quick Start**](#quick-start) **|** [**Example**](#example-program-a-basic-llm-call) **|** [**GUI**](#graphical-experience) **|** [**Key Features**](#key-features) **|** [**Documentation**](#documentation) **|** [**Documentation**](#documentation) **|** [**API Cheat Sheet**](#api-cheat-sheet)
+[**Quick Start**](#quick-start) **|** [**Example**](#example-program-a-basic-llm-call) **|** [**GUI**](#graphical-experience) **|** [**Key Features**](#key-features) **|** [**Documentation**](#documentation) **|** [**API Cheat Sheet**](#api-cheat-sheet)
 
 ## Quick Start