cli: add env var doc

[anshumanv]

Added and env var to disable local import

webpack/webpack-cli#2546

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[anshumanv]

This doesn't really come in config env so I'm skeptical about keeping it here

[chenxsan]

Or we can add a third column in the table indicating whether the item is available in the env.

[snitin315]

Or we can add a third column in the table indicating whether the item is available in the env.

Sounds good to me.

[anshumanv]

yeah that makes sense, will update

[snitin315]

@anshumanv can you also add WEBPACK_PACKAGE while you are at it? webpack/webpack-cli#2556

[anshumanv]

yep lets do it

[chenxsan]

Will merge it when a new version webpack-cli is out.

[anshumanv]

lets merge