fix(types): improve e.detail type for dispatched events (#1907)

* fix(types): improve `e.detail` type for dispatched events

* Run "yarn build:docs"

* test: assert new types

tests/Slider.test.svelte

@@ -11,6 +11,9 @@
   maxLabel="990 MB"
   value="{100}"
   fullWidth
+  on:change="{(e) => {
+    console.log(e.detail); // number
+  }}"
 />
 
 <Slider

tests/StructuredList.test.svelte

@@ -11,7 +11,13 @@
   import CheckmarkFilled from "carbon-icons-svelte/lib/CheckmarkFilled.svelte";
 </script>
 
-<StructuredList>
+<StructuredList
+  selection
+  selected="row-1-value"
+  on:change="{(e) => {
+    console.log(e.detail); // string
+  }}"
+>
   <StructuredListHead>
     <StructuredListRow head>
       <StructuredListCell head>Column A</StructuredListCell>

tests/Tabs.test.svelte

@@ -2,7 +2,11 @@
   import { Tabs, Tab, TabContent, TabsSkeleton } from "../types";
 </script>
 
-<Tabs>
+<Tabs
+  on:change="{(e) => {
+    console.log(e.detail); // number
+  }}"
+>
   <Tab label="Tab label 1" />
   <Tab label="Tab label 2" />
   <Tab label="Tab label 3" />