Update .CONTRIBUTING.md

Co-authored-by: Erin Shaben <[email protected]>

Author: brunopgalvao

.CONTRIBUTING.md

@@ -258,9 +258,9 @@ Available categories for tutorials are found in [scripts/llms_config.json](./scr
 
 **Requirements**:
 
-- Format: `.webp`
-- Desktop screenshots: 1512px width, variable height
-- Browser extension screenshots: 400x600px
+- **Format**: `.webp`
+- **Desktop screenshots**: 1512px width, variable height
+- **Browser extension screenshots**: 400x600px
 
 **How to use**: