Fix typo in button.mdx (#735)

content/components/button.mdx

@@ -70,7 +70,7 @@ Buttons allow users to initiate an action or command when clicked or tapped. The
   />
   <Box as="p" mt="0">
     <h4>Leading visuals</h4>
-    Leading visuals provide additional context for a button label, such as a “search” icon next to the label for a search field submit. Leading visuals always apear locked to the button label, even if the button is full width.
+    Leading visuals provide additional context for a button label, such as a “search” icon next to the label for a search field submit. Leading visuals always appear locked to the button label, even if the button is full width.
 
   </Box>
 </Box>