Create the build:dev npm script aliased to the current build script

[layoutd]

Changes proposed in this Pull Request:

Adding the build:dev npm script for consistency with other projects. It's currently just aliased to the existing build script, although it seems like build in most repos actually ends by building the archive.

Detailed test instructions:

1. See that both npm run build and npm run build:dev work and do the same thing (build assets and translations.

[ecgan]

Tested. They kinda work the same - they both build assets and translations.

However, npm run build:dev does not trigger prebuild (to run composer install) and postbuild (creating zip archive).

I am wondering: why do we want to add this build:dev script, since it is doing "the same thing"? Is there a pain point that you are experiencing from its inconsistency with other projects? 🤔

I looked into https://github.com/woocommerce/google-listings-and-ads/blob/e95a1151cc3ed9dcb902ead95e65c1cd3cc6ff1b/package.json#L93 and I think it has pretty good setup there (look for build and dev npm scripts). Maybe we can use that as a reference?

[layoutd]

I am wondering: why do we want to add this build:dev script, since it is doing "the same thing"? Is there a pain point that you are experiencing from its inconsistency with other projects? 🤔

My thought process is essentially to reduce brain cycles. We have a bit of a hodgepodge of commands: some repos use build:dev, some use dev, and this one currently uses build. My end goal is standardize the command to build all our extensions for easier testing when jumping across repos (think: compatibility testing, etc.).

[ecgan]

Okay, let's do it! 👍 We can iterate on it along the way. 🙂

[layoutd]

Thanks for the assistance and feedback, @ecgan 🙇🏻