When I want to open it with ng serve --open it gives me “The serve command requires to be run in an Angular project, but a project definition could not be found.”
I have also created a new angular project with “ng new timestamp-microservice” but that creates a project in the mentioned folder which does not include the boilerplate-npm files.
It is great you want to further the project outside the scope of the lessons. However, this boilerplate is as simple as possible, because the lessons focus on teaching npm (Node Package Manager).
I am not sure what you would gain from adding Angular to the project, as you do not use the frontend during these lessons.
These lessons are very simple, and you do not end up with much of an app, after completing them.
Fortunately, the 5 projects at the end of the section are more complex, and do require a frontend. For these, it would absolutely make sense to integrate a frontend framework.
I am unsure how to do this with Angular, but I cannot imagine it requires much more than:
Install Angular
Set config to watch files in new src directory
Build to public
Serve public assets
I will mention this: This curriculum teaches the MERN stack; you are welcome to replace React with Angular, but it is expected you will use Node and Express to serve your app. Otherwise, for this section, you are not really following the curriculum, and cannot expect the tests to be reliable.
Anyway. Continue on your way, and be sure to pop by, if you later get stuck.