Add missing data-ch-theme attributes

Author: pomber

packages/mdx/dev/content/test.mdx

@@ -7,3 +7,9 @@ function foobarloremipsumfoobarloremipsumsitametfoobarloremipsumfoobarloremipsum
   return 8
 }
 ```
+
+<CH.Preview>
+
+Hello
+
+</CH.Preview>

packages/mdx/src/mdx-client/preview.tsx

@@ -6,6 +6,7 @@ import {
   SandboxInfo,
 } from "@codesandbox/sandpack-client"
 import { EditorStep } from "../mini-editor"
+import { CodeConfig } from "../smooth-code"
 
 export type PresetConfig = SandboxInfo
 export function Preview({
@@ -16,6 +17,7 @@ export function Preview({
   children,
   style,
   frameless,
+  codeConfig,
   ...rest
 }: {
   className: string
@@ -25,6 +27,7 @@ export function Preview({
   show?: string
   style?: React.CSSProperties
   children?: React.ReactNode
+  codeConfig?: CodeConfig
 }) {
   const kids = presetConfig ? (
     <SandpackPreview
@@ -40,6 +43,7 @@ export function Preview({
         "ch-preview" + (className ? " " + className : "")
       }
       style={style}
+      data-ch-theme={codeConfig?.themeName}
     >
       {frameless ? (
         kids

packages/mdx/src/mdx-client/slideshow.tsx

@@ -97,6 +97,7 @@ export function Slideshow({
         withPreview ? "ch-slideshow-with-preview" : ""
       } ${className || ""}`}
       style={style}
+      data-ch-theme={codeConfig.themeName}
     >
       <div className="ch-slideshow-slide">
         <InnerCode