Add smallpt as an example notebook

[anutosh491]

Description

Please include a summary of changes, motivation and context for this PR.

Replicating https://www.kevinbeason.com/smallpt/ through xeus-cpp-lite

Type of change

Please tick all options which are relevant.

• Bug fix
• New feature
• Added/removed dependencies
• Required documentation updates

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.72%. Comparing base (ed69a4c) to head (0656b04).

Additional details and impacted files

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  Coverage   80.72%   80.72%           
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  Files          19       19           
  Lines         970      970           
  Branches       93       93           
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  Hits          783      783           
  Misses        187      187           

[vgvassilev]

Why was this reverted?

[anutosh491]

oops, I think I had messed up a tad bit here (I just realized this)

Hey @vgvassilev ,

If you remember we had attempted to add the example notebook for smallpt in our codebase. And then I had made a commit to revert this patch #236

The reason for the revert was this

1. As you see I moved a level above sysroot/include here to just sysroot. So obviously we were preloading much more than we wanted in our file system. So our builds had this warning

warning: file packager is creating an asset bundle of 582 MB. this is very large, and browsers might have trouble loading it. see https://hacks.mozilla.org/2015/02/synchronous-execution-and-filesystem-access-in-emscripten/

2. So though stuff was running locally pretty smoothly .... our deployment was having trouble loading the xcpp.data file which turned out to be huge as the warning said.

Hence the revert.

What I just realized is all SDL headers also lie inside the sysroot/include location (not sure if this was changed as we shifted to emscripten 3.1.73 or so)

(base) anutosh491@Anutoshs-MacBook-Air SDL % pwd
/Users/anutosh491/work/emsdk/upstream/emscripten/cache/sysroot/include/SDL
(base) anutosh491@Anutoshs-MacBook-Air SDL % ls
COPYING                 SDL_config.h            SDL_config_pandora.h    SDL_gesture.h           SDL_keycode.h           SDL_opengl.h            SDL_render.h            SDL_syswm.h             begin_code.h
SDL.h                   SDL_config.h.in         SDL_config_windows.h    SDL_gfxPrimitives.h     SDL_loadso.h            SDL_opengles.h          SDL_revision.h          SDL_thread.h            close_code.h
SDL_assert.h            SDL_config_android.h    SDL_config_wiz.h        SDL_haptic.h            SDL_log.h               SDL_opengles2.h         SDL_rotozoom.h          SDL_timer.h
SDL_atomic.h            SDL_config_emscripten.h SDL_copying.h           SDL_hints.h             SDL_main.h              SDL_pixels.h            SDL_rwops.h             SDL_touch.h
SDL_audio.h             SDL_config_iphoneos.h   SDL_cpuinfo.h           SDL_image.h             SDL_mixer.h             SDL_platform.h          SDL_scancode.h          SDL_ttf.h
SDL_blendmode.h         SDL_config_macosx.h     SDL_endian.h            SDL_input.h             SDL_mouse.h             SDL_power.h             SDL_shape.h             SDL_types.h
SDL_clipboard.h         SDL_config_minimal.h    SDL_error.h             SDL_joystick.h          SDL_mutex.h             SDL_quit.h              SDL_stdinc.h            SDL_version.h
SDL_compat.h            SDL_config_nintendods.h SDL_events.h            SDL_keyboard.h          SDL_name.h              SDL_rect.h              SDL_surface.h           SDL_video.h

Which means are already having access to the SDL header right now. We don't need to change nothing with preloading and we should definitely be able to add this example !

[anutosh491]

#299