dillon1000/react

Write artifacts to `build` instead of `build2`

Now that all the CI jobs have been migrated to the new build script,
we can start renaming the `build2` directory to `build`.

Since there are lots of scripts that reference `build2`, including
downstream scripts that live outside this repo, I'm going to keep
the `build2` directory around as a copy of `build`.

Then once all the references are updated, I will delete the copy.