Update README.md

README.md

@@ -25,7 +25,7 @@ VietAlpha brings that record into digital form, studies it as history of mathema
 
 ## Research principles
 
-- **Data first** Keep the source, transcription, and provenance traceable.
+- **Data first:** Keep the source, transcription, and provenance traceable.
 - **Focused on Vietnamese mathematics:** Build around Vietnamese language, notation, curriculum, and source materials.
 - **Open access for students:** Make the knowledge and tools publicly available and useful.