[request] standalone version of file_packager.py

Currently to package files we need to use `file_packager.py` - this requires the installation of python.

I also notice that if I just clone this repo and attempt to execute `file_packager.py` with python installed:
```
file_packager: warning: config file not found: C:\Users\daego\Desktop\Projects\emscripten\.emscripten. You can create one by hand or run `emcc --generate-config`
file_packager: error: LLVM_ROOT not set in config (C:\Users\daego\Desktop\Projects\emscripten\.emscripten), and `clang` not found in PATH
```
signalling even more dependencies,
Which aren't even mentioned https://emscripten.org/docs/porting/files/packaging_files.html