[docs] Update hello-world.md in SDK32 too (#3622)
[docs] Update hello-world.md in SDK32 too (#3622)

few spelling mistakes in 'What now?' section.
exponentjs/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent