Update style-guide.md

Author: mattstuddert

style-guide.md

@@ -7,6 +7,8 @@ The designs were created to the following widths:
 - Mobile: 375px
 - Desktop: 1440px
 
+> 💡 These are just the design sizes. Ensure content is responsive and meets WCAG requirements by testing the full range of screen sizes from 320px to large screens.
+
 ## Colors
 
 ### Primary
@@ -32,3 +34,5 @@ The designs were created to the following widths:
 
 - Family: [Poppins](https://fonts.google.com/specimen/Poppins)
 - Weights: 200, 400, 600
+
+> 💎 [Upgrade to Pro](https://www.frontendmentor.io/pro?ref=style-guide) for design file access to see all design details and get hands-on experience using a professional workflow with tools like Figma.