[cli] support for ES6

Description

$ ./node_modules/.bin/jss convert dist/colors.js -f css
evalmachine.<anonymous>:1
export default
^^^^^^

SyntaxError: Unexpected token export

module.exports = {

Contributor guide

Tech stack

javascriptnodejs

Domain

clitooling

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-3 hours

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

fresh

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

node.jsCLI toolsES6 modules

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

60

Research direction

Investigate the jss cli source code, likely in the convert command, to see how the export format is implemented (using the ` e` flag). Then determine where to add an import format flag (e.g., ` i es6`). The code is in the jss/packages/jss cli directory. Refer to the existing implementation for guidance.