[jest] Add comments explaining the jest proxy script re: debugging
[jest] Add comments explaining the jest proxy script re: debugging

Closes #3528

exponent/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponentjs/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent