Add Bridge2AI datasheet links and fix directory structure links

Changes:
- Add prominent section with working GitHub Pages links to curated datasheets for all 4 Bridge2AI Generating Centers (AI-READI, CM4AI, VOICE, CHORUS)
- Link to full D4D examples page
- Fix Repository Structure section: remove broken relative directory links, use plain text instead
- All links now point to rendered HTML on GitHub Pages (not GitHub repository)

Author: realmarcin

README.md

@@ -13,17 +13,26 @@ This repository stores a LinkML schema representation for the original Datasheet
 
 We are also tracking related developments, such as augmented Datasheets for Datasets models as in [Augmented Datasheets for Speech Datasets and Ethical Decision-Making](https://dl.acm.org/doi/10.1145/3593013.3594049).
 
+## Bridge2AI Generating Center Datasheets
+
+Curated comprehensive datasheets for each Bridge2AI data generating project:
+
+* **[AI-READI](https://bridge2ai.github.io/data-sheets-schema/html_output/concatenated/curated/AI_READI_human_readable.html)** - Retinal imaging and diabetes dataset
+* **[CM4AI](https://bridge2ai.github.io/data-sheets-schema/html_output/concatenated/curated/CM4AI_human_readable.html)** - Cell maps for AI dataset
+* **[VOICE](https://bridge2ai.github.io/data-sheets-schema/html_output/concatenated/curated/VOICE_human_readable.html)** - Voice biomarker dataset
+* **[CHORUS](https://bridge2ai.github.io/data-sheets-schema/html_output/concatenated/CHORUS_d4d_alldocs.html)** - Health data for underrepresented populations
+
+[View all D4D examples →](https://bridge2ai.github.io/data-sheets-schema/d4d_examples.html)
+
 ## Repository Structure
 
-* [examples/](examples/) - example data
-* [project/](project/) - project files (do not edit these)
-* [src/](src/) - source files (edit these)
-  * [data_sheets_schema](src/data_sheets_schema)
-    * [schema](src/data_sheets_schema/schema) -- LinkML schema
-      (edit this)
-    * [datamodel](src/data_sheets_schema/datamodel) -- generated
-      Python datamodel
-* [tests/](tests/) - Python tests
+* `examples/` - example data
+* `project/` - project files (do not edit these)
+* `src/` - source files (edit these)
+  * `data_sheets_schema/`
+    * `schema/` - LinkML schema (edit this)
+    * `datamodel/` - generated Python datamodel
+* `tests/` - Python tests
 
 ## D4D Metadata Generation