One thing that you might have noticed while we were using the debugging in the web browser before is that we only had access to the JavaScript code (as opposed to the TypeScript code when debugging with VS Code directly). In our case, with TodoIt, it is okay because the program is very simple, and so it remains intuitive. But in larger applications, this will simply not be usable.
This is why a feature called source maps is really, really valuable. Source maps are mapping files that create the link between lines in the JavaScript sources and the corresponding ones in the original source code (TypeScript source code, in our case).
Source maps can either be stored in the JavaScript files themselves, in which case, they are called inline source maps or in the separate (that is, external) .map files.
We won't dive much more into the...