docs: add node documentation guide to README

Add comprehensive guide for accessing and using documentation on core MultiGPU and DisTorch2 nodes, covering 36+ nodes with detailed parameters, outputs, and usage examples. This enhances user experience by providing easy reference for standard ComfyUI loaders and DisTorch2 features, while clarifying coverage excludes third-party nodes.

Author: pollockjj

README.md

@@ -112,6 +112,15 @@ Currently supported nodes (automatically detected if available):
 
 All MultiGPU nodes available for your install can be found in the "multigpu" category in the node menu.
 
+## Node Documentation
+
+Detailed technical documentation is available for all **automatically-detected core MultiGPU and DisTorch2 nodes**, covering 36+ documented nodes with comprehensive parameter details, output specifications, and DisTorch2 allocation guidance where applicable.
+
+- **To access documentation**: Right-click on any core MultiGPU or DisTorch2 node in ComfyUI and select "Help" from the context menu
+- **Coverage**: All standard ComfyUI loader nodes (UNet, VAE, Checkpoints, CLIP, ControlNet, Diffusers) plus popular GGUF loader variants
+- **Contents**: Input parameters with data types and descriptions, output specifications, usage examples, and DisTorch2 distributed loading explanations with allocation modes and strategies
+- **Note**: Documentation covers core ComfyUI-MultiGPU functionality only. Third-party custom node integrations (WanVideoWrapper, Florence2, etc.) have their own separate documentation.
+
 ## Example workflows
 
 All workflows have been tested on a 2x 3090 + 1060ti linux setup, a 4070 win 11 setup, and a 3090/1070ti linux setup.