Add prominent System Card links to README.md

- Add prominent System Card link after main description with emoji
- Update existing System Card reference with Hugging Face Hub URL
- Link points to: https://huggingface.co/undertheseanlp/sonar_core_1/blob/main/Sonar%20Core%201%20-%20System%20Card.md
- Improves discoverability of detailed model documentation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -68,6 +68,8 @@ pipeline_tag: text-classification
 
 A machine learning-based text classification model designed for Vietnamese language processing. Built on TF-IDF feature extraction pipeline combined with Logistic Regression, achieving **92.33% accuracy** on VNTC (news) and **70.96% accuracy** on UTS2017_Bank (banking) datasets.
 
+📋 **[View Detailed System Card](https://huggingface.co/undertheseanlp/sonar_core_1/blob/main/Sonar%20Core%201%20-%20System%20Card.md)** for comprehensive model documentation, performance analysis, and limitations.
+
 ## Model Description
 
 **Sonar Core 1** is a Vietnamese text classification model that supports multiple domains including news categorization and banking text classification. The model is specifically designed for Vietnamese news article classification, banking text categorization, content categorization for Vietnamese text, and document organization and tagging.
@@ -318,7 +320,7 @@ for text in examples:
 - **Repository**: https://huggingface.co/undertheseanlp/sonar_core_1
 - **Framework Version**: scikit-learn ≥1.6
 - **Python Version**: 3.10+
-- **System Card**: See "Sonar Core 1 - System Card.md" for detailed documentation
+- **System Card**: See [Sonar Core 1 - System Card](https://huggingface.co/undertheseanlp/sonar_core_1/blob/main/Sonar%20Core%201%20-%20System%20Card.md) for detailed documentation
 
 ## Citation