Minor node.js packaging issue for ecore.xmi

[pgaufillet]

When using the XMI variant of ecore.js with node.js, the require directive looks like ecore = require('ecore/dist/ecore.xmi'); in place of the usual ecore = require('ecore');

It would be better to support symetrically ecore = require('ecore.xmi');

[vsimko]

or just for all cases

const ecore = require('ecore')