new-sample: Embed ChakraCore using CMake

[obastemur]

Linux / Windows / OSX

Embed ChakraCore via CMake using ChakraCoreEmbed.cmake as shown from CMakeLists.txt

[obastemur]

Once this merged, will also make this part of test/native-tests under ChakraCore to make sure keeping ChakraCoreEmbed.cmake up to date.

[obastemur]

Sample command line usage:

Windows

> cmake . -DCHAKRACORE_PATH=<ChakraCore Path> -G "Visual Studio 14 2015 Win64"
> msbuild /p:Platform=x64 HelloWorld.sln

> Debug\Sample.exe

Linux/OSX

> cmake . -DCHAKRACORE_PATH=<ChakraCore Path>
> make

> ./Sample

[liminzhu]

@obastemur good stuff 👍 ! Can you add a readme like this one documenting the proper build & run steps for different platforms?

[obastemur]

Added README, @liminzhu Thanks for review.