fix: Explanaitions typo on index.md (explodinggradients#801)

Noticed this typo and figured I'd offer to fix it


![image](https://github.com/explodinggradients/ragas/assets/71190106/fcb948fd-5deb-41d0-bb59-df50efe8e62b)

![image](https://github.com/explodinggradients/ragas/assets/71190106/d29ad796-6945-43a5-abdb-b6fd9be3a604)

docs/index.md

@@ -26,7 +26,7 @@ against and setting up online monitoring for your RAG apps.
 :link: core-concepts
 :link-type: ref
 
-The high-level explainations for building a better understand about the
+The high-level explanations for building a better understand about the
 important topics such how to think about metrics-driven development, how the Ragas metrics work under the hood and synthetic dataset generation.
 :::
 :::{grid-item-card} 🛠️ How-to Guides