Add DiMB-RE

## Adding a Dataset
- **Name:** DiMB-RE
- **Description:** We developed DiMB-RE, a comprehensive corpus annotated with 15 entity types
(e.g., Nutrient, Microorganism) and 13 relation types (e.g., INCREASES, IMPROVES) capturing
diet-microbiome associations.
- **Task:** NER, RE
- **Paper:** https://arxiv.org/pdf/2409.19581
- **Data:** https://github.com/ScienceNLP-Lab/DiMB-RE
- **License:** Unknown

Start by reviewing the dataset details, paper, and linked DiMB-RE repository to understand the corpus and its license status. Then inspect how this project records other biomedical datasets and identify the appropriate curation entry point. Done means DiMB-RE is added consistently with the project's existing dataset records, with its access and licensing information confirmed.

Written by the indexing model from the issue text.