Adding code coverage

Would be great if code coverage was added to this. I'm working on getting it working with karma-coverage, but the instructions all don't really support @angular/cli and don't support webpack.

Start by reviewing the repository's current Karma and Jasmine setup alongside the @angular/cli and webpack configuration. Investigate whether karma-coverage supports this setup and identify the project instructions that need updating. Done means code coverage can be generated for the example project using its documented test workflow.

由索引模型根据 Issue 内容生成。