docs: added structure to sidebar (#2120)

Author: jjmachan

docs/experimental/explanation/datasets.md renamed to docs/experimental/core_concepts/datasets.md

@@ -10,11 +10,11 @@
 
     [:octicons-arrow-right-24: Tutorials](tutorials/index.md)
 
-- 📚 **Explanations**
+- 📚 **Core Concepts**
 
     In depth explanation and discussion of the concepts and working of different features available in Ragas.
 
-    [:octicons-arrow-right-24: Explanations](explanation/index.md)
+    [:octicons-arrow-right-24: Core Concepts](core_concepts/index.md)
 
 
 </div>

docs/experimental/explanation/experimentation.md renamed to docs/experimental/core_concepts/experimentation.md

@@ -78,6 +78,17 @@ nav:
           - concepts/feedback/index.md
   - 🧪 Experimental:
     - Overview: experimental/index.md
+    - Tutorials:
+        - experimental/tutorials/index.md
+        - Agent: experimental/tutorials/agent.md
+        - Prompt: experimental/tutorials/prompt.md
+        - RAG: experimental/tutorials/rag.md
+        - Workflow: experimental/tutorials/workflow.md
+    - Core Concepts:
+        - experimental/core_concepts/index.md
+        - Datasets: experimental/core_concepts/datasets.md
+        - Experimentation: experimental/core_concepts/experimentation.md
+        - Metrics: experimental/core_concepts/metrics.md
   - 🛠️ How-to Guides:
       - howtos/index.md
       - Customizations: