Update Navigation column in breakpoints table (#7015)

Co-Authored-By: Aaron Casanova <32409546+aaronccasanova@users.noreply.github.com>

Co-authored-by: Aaron Casanova <32409546+aaronccasanova@users.noreply.github.com>

Author: lgriffee

.changeset/slimy-vans-doubt.md

@@ -0,0 +1,5 @@
+---
+'polaris.shopify.com': patch
+---
+
+Update navigation column in breakpoints table for MD breakpoint

polaris.shopify.com/content/foundations/design/space/index.md

@@ -118,7 +118,7 @@ The grid adapts to the viewport width. The amount of columns will change dependi
 | ---------------------------------------- | ------- | ------ | ------ | ---------- |
 | **XS** <br/> 0-489 <br/> Phones          | 6       | 16     | 16     | Collapsed  |
 | **SM** <br/> 490-767 <br/> Small tablets | 6       | 16     | 16     | Collapsed  |
-| **MD** <br/> 768-1039 <br/> Tablets      | 6       | 24     | 16     | Collapsed  |
+| **MD** <br/> 768-1039 <br/> Tablets      | 6       | 24     | 16     | Visible    |
 | **LG** <br/> 1040-1399 <br/> Laptops     | 12      | 24     | 16     | Visible    |
 | **XL** <br/> 1440+ <br/> Desktops        | 12      | 32     | 16     | Visible    |