add option to disable env expanding in plugin-dotenv

[tudddorrr]

Changes

Changed the dotenv-expand functionality to be configurable via an expand option (defaults to true). Sometimes you don't want env expansion if you want to run something like envsubst on your built files.

Testing

Added a new expandable variable and snapshot tests for when the option is on/off.

Docs

Yes, added expand option to config table.

[changeset-bot]

🦋 Changeset detected

Latest commit: 3281a0c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@snowpack/plugin-dotenv	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/pikapkg/snowpack/9vY27MagtwMr7pxCDR8dhdoGRH3s
✅ Preview: https://snowpack-git-fork-tudddorrr-main-pikapkg.vercel.app

[drwpow]

Awesome! This is a great feature.

If it’s all right with you, though, this is technically breaking behavior so I’ll treat this as a major change. But other than that, LGTM! Nice tests, too.

[drwpow]

Actually, nevermind; I see that you added the option with a default of true so this is indeed minor. Will keep as-is!

[tudddorrr]

Thanks @drwpow !