Fix style guide /visuals/* links to /design/* (#1788)

Author: kaelig

src/components/Caption/README.md

@@ -36,7 +36,7 @@ Caption text size is smaller than the recommended size for general reading. It s
 
 ### Captions
 
-Captions are primarily used in [data visualizations](/visuals/data-visualizations). Stick to a few words and don’t use this component for complete sentences or longer content.
+Captions are primarily used in [data visualizations](/design/data-visualizations). Stick to a few words and don’t use this component for complete sentences or longer content.
 
 <!-- usagelist -->
 

src/components/EmptyState/README.md

@@ -41,7 +41,7 @@ Empty states should:
 - Be encouraging and never make merchants feel unsuccessful or guilty because
   they haven’t used a product or feature
 - Explain the steps a merchant needs to take to activate a product or feature
-- Use illustrations thoughtfully as outlined in our [illustration guidelines](/visuals/illustrations)
+- Use illustrations thoughtfully as outlined in our [illustration guidelines](/design/illustrations)
 - Use only one primary call-to-action button
 
 ---
@@ -161,6 +161,6 @@ Use to explain a single feature before a merchant has used it.
 
 ## Related components
 
-- To learn more about illustrations for empty states, [read the illustration guidelines](/visuals/illustrations)
+- To learn more about illustrations for empty states, [read the illustration guidelines](/design/illustrations)
 - To create page-level layout, [use the layout component](/components/structure/layout)
 - To highlight a Shopify feature, [use the callout card component](/components/structure/callout-card)

src/components/ExceptionList/README.md

@@ -39,7 +39,7 @@ Exception lists aren’t clickable. If you’re a partner and have an idea that
 Exception lists should:
 
 - Highlight an exceptional state that helps the merchant make a decision
-- Use the appropriate [color](https://polaris.shopify.com/visuals/colors) to suit the tone of the message
+- Use the appropriate [color](https://polaris.shopify.com/design/colors) to suit the tone of the message
 - Have a description (a title is optional)
 - Be concise
 

src/components/ResourceList/README.md

@@ -1540,7 +1540,7 @@ In the CSS itself, we’re going to start mobile first. We’ll open up the CSS
 }
 ```
 
-Note that we’ve annotated the colors here to show that they correspond to the [Polaris color palette](https://polaris.shopify.com/visuals/colors#section-color-palette).
+Note that we’ve annotated the colors here to show that they correspond to the [Polaris color palette](https://polaris.shopify.com/design/colors#section-color-palette).
 
 Now that we have our small screen layout, we can layer on the layouts for medium and wide screens. This requires some additional wrappers. With this extra markup, it’s a good time to split out some of this out to clean up the code: