feat: experimental support for shiki

Author: nico-bachner

example.md

@@ -1,5 +1,6 @@
 ---
 theme: ./
+highlighter: shiki
 ---
 
 # Slidev Theme Geist

package.json

@@ -28,7 +28,7 @@
                 "sans": "Inter",
                 "mono": "Menlo"
             },
-            "highlighter": "prism"
+            "highlighter": "shiki"
         }
     },
     "scripts": {

setup/shiki.ts

@@ -3,8 +3,8 @@ import { defineShikiSetup } from '@slidev/types'
 export default defineShikiSetup(async({ loadTheme }) => {
   return {
     theme: {
-      dark: await loadTheme(require.resolve('theme-vitesse/themes/vitesse-dark.json')),
-      light: await loadTheme(require.resolve('theme-vitesse/themes/vitesse-light.json')),
+      dark: await loadTheme(require.resolve('./shiki/dark.json')),
+      light: await loadTheme(require.resolve('./shiki/light.json')),
     },
   }
 })