Clarify resource management in emscripten chapter

[eliemichel]

From Delhills on Discord:

Does anyone know how to load the files (shaders, meshes, ...) from emscripten (or have any resource where it's explained)? I tried to follow Élie's CMakeLists code in step 95 but I don't quite understand it and it doesn't work 😟

In case someone has the same problem as me when using emscripten, if you add "--preload-file "${CMAKE_CURRENT_SOURCE_DIR}/resources" in target_link_options inside CMakeLists then remove the "-d build-web" in the command to run the server (python -m http.server) and then access the url "localhost:8000/build-web/App.html" and it should work

(I'm going to fix this thx! Also I'm considering putting the emscripten part much earlier in the main part of the guide)