feat(combobox docs): add no-chevron reasoning (#4070)

* feat(combobox docs): add no-chevron reasoning

* fix: remove extra import and fix heading level

* chore: add back old import

* chore: add marginY to Callout

Author: serifluous

packages/paste-website/src/pages/components/combobox/index.mdx

@@ -138,6 +138,11 @@ This is useful when a user needs to filter a list of options, or when there are
 users may find it difficult to navigate with only scrolling. Pass the `autocomplete` prop to enable
 the feature.
 
+<Callout variant="neutral" marginY="space70">
+    <CalloutHeading as="h4">Why doesn't the autocomplete Combobox have a chevron?</CalloutHeading>
+    <CalloutText>The autocomplete Combobox doesn't have a chevron because it's often used as a search input, where showing a chevron could be confusing.</CalloutText>
+</Callout>
+
 <LivePreview scope={{Combobox}} noInline language="jsx" showOverflow>
   {autoCompleteExample}
 </LivePreview>