Re-export type-guard functions #61
Description
The package defines type guards in src/editv2.ts (e.g., isRemove, isSetAttributes, isInsert, isEditV2), but the root entry only re-exports types. For testing it would be cool to re-export the guards from src/oscd-api.ts (e.g., export { isRemove, ... } from './editv2.js') so they are available via @openscd/oscd-api.