chore: add codemirror to libundler externals

Author: surmon-china

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ### 5.1.0 (2022-06-12)
 
-- Update codemirror dependencies to 6.x
+- Upgrade codemirror dependencies to 6.x
 - The package no longer exports `@codemirror/view` `@codemirror/state` `@codemirror/basic-setup`.
 - Change the package [from `@codemirror/example-setup` to just `codemirror`](https://github.com/codemirror/basic-setup/blob/main/CHANGELOG.md#breaking-changes).
 

libundler.config.ts

@@ -6,6 +6,6 @@ export default defineConfig({
   entry: './src/index.ts',
   outDir: './dist',
   targets: ['esm', 'cjs'],
-  external: ['vue', 'csstype', /@codemirror\/.*/],
+  external: ['vue', 'csstype', 'codemirror', /@codemirror\/.*/],
   exports: 'named'
 })