architect/plugin-lambda-invoker

AI Summary: Update the documentation for the `@architect/plugin-lambda-invoker` plugin to clarify the supported file extensions and module systems for `sandbox-invoke-mocks` files. Specifically, address the incompatibility between using `.js` files with projects configured as ES modules (`"type": "module"` in `package.json`). The documentation should explicitly state that `.mjs` files are required for ES modules projects, while `.js` files are suitable for CommonJS projects.