Add comprehensive dataset upload guide for LLMs (experimental guide)

- Add new guide specifically designed to help LLMs assist users with dataset uploads
- Covers decision workflow, built-in loaders, custom format conversion, and validation
- Includes practical examples for various data types and upload scenarios
- Add entry to table of contents under Datasets section

Author: davanstrien

docs/hub/_toctree.yml

@@ -164,6 +164,8 @@
     title: Gated Datasets
   - local: datasets-adding
     title: Uploading Datasets
+  - local: datasets-upload-guide-llm
+    title: Dataset Upload Guide (LLM)
   - local: datasets-downloading
     title: Downloading Datasets
   - local: datasets-libraries
@@ -233,6 +235,11 @@
         title: Image Dataset
       - local: datasets-video
         title: Video Dataset
+  - local: datasets-research-guide
+    title: Research Datasets Guide
+    sections:
+      - local: datasets-research-science
+        title: Science & Scientific Computing
 - local: spaces
   title: Spaces
   isExpanded: true