Add dataset upload guide for LLMs (experimental guide) (#1830)

* 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

* Add 'Working Without File Access' section to LLM guide

- Add commands for LLMs to request when they don't have direct file access
- Includes tree/find commands for structure, du/ls for sizes, head for data preview
- Helps LLMs guide users on web interfaces (Claude, ChatGPT browser)
- Placed early in guide for immediate visibility

* Fix toctree to only include LLM guide entry

- Remove unintended changes from other work
- Keep only the addition of datasets-upload-guide-llm entry

* Add machine-readable hub limits in YAML format

- Add structured YAML block with Hub constraints for LLM parsing
- Helps prevent hallucination of limits by providing exact values
- Include comments explaining each limit
- Keep human-readable summary alongside machine format

* address comments

* Update docs/hub/_toctree.yml

Co-authored-by: Julien Chaumond <julien@huggingface.co>

* nicer tip formatting

---------

Co-authored-by: Julien Chaumond <julien@huggingface.co>

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: Uploading Datasets (for LLMs)
   - local: datasets-downloading
     title: Downloading Datasets
   - local: datasets-libraries