emscripten build requires res/OpenSans-Regular.ttf in project directory
emscripten build requires res/OpenSans-Regular.ttf in project directory, but this is not created by init code.

reproduce:

```sh
$ echo import nimx/naketools > nakefile.nim
$ nake emscripten
```

Expected: Compile
Actual: Error message

Workaround:

```sh
mkdir ref
curl https://github.com/yglukhov/nimx/blob/master/test/res/OpenSans-Regular.ttf -o res/OpenSans-Regular.ttf
$ nake emscripten
```

Now it compiles