feat: export VirtualFileSystem and FileBuffer

Author: thetutlage

index.ts

@@ -11,4 +11,6 @@ export { hooks } from './src/hooks.ts'
 export { Bundler } from './src/bundler.ts'
 export { DevServer } from './src/dev_server.ts'
 export { TestRunner } from './src/test_runner.ts'
+export { FileBuffer } from './src/file_buffer.ts'
+export { VirtualFileSystem } from './src/virtual_file_system.ts'
 export { SUPPORTED_PACKAGE_MANAGERS } from './src/bundler.ts'