Suggest to forbid shadowing of global variables

[dominique-pfister]

Every now and then, I embarrassingly add a process function in a non-class file (e.g. an OpenWhisk action) that should process some input. This happily shadows the process global object in that file, leaving me baffled for some time until I find the problem.

Is there a reason we don't forbid shadowing global variables in:

helix-eslint-config/index.js

Lines 57 to 59 in 3960a51

	'no-shadow': ['error', {
	allow: ['_'],
	}],

by adding:

          builtinGlobals: true,