docs: fix broken Project structure TOC anchor

Author: adrian-niculescu

README.md

@@ -21,7 +21,7 @@ The new runtime is based on the Node-API and is designed to be more stable, fast
 
 <!-- TOC depthFrom:2 -->
 
-- [Main Projects](#main-projects)
+- [Project structure](#project-structure)
 - [Helper Projects](#helper-projects)
 - [Build Prerequisites](#build-prerequisites)
 - [How to build](#how-to-build)