The resulting Ink builds had bad image paths that were breaking any

post-processing, consumption or the build, and references to the images.

We have a couple images that we normally try to inline into the CSS, but

due to path issues in the build setup, we'd end up instead generating

CSS that referenced relative paths.
There were a couple things going wrong here:


We had an @images-path variable in LessCSS that was used to link to

   the Ink images, but this could conflict with consumers and was

   referencing an ink directory that wasn't going to consistently

   exist in the build process between local builds and remote

   consumption.


We were generating bad sourcemaps due to what appears to be issues in

cleancss, depending on where it's run.


We had some build configuration missing that impacted lookup of

Spina from the global object.


This change redoes a lot of our build process to address this. We're now

using Rollup for all builds, rather than scripts within package.json.
We build the CSS at the same time we build our TypeScript types file. We

have to key off rules based on some JavaScript file, so we choose that,

since it only produces one output, ensuring we only do this work once.
The order of operations is more closely managed, as well as the

directory in which we're running cleancss, helping to resolve

previously-hidden warnings about sourcemaps.
For the image references, we now have an @ink-path variable that

points to @beanbag/ink/lib, which is what would be needed by consumers

of the LEss files. Paths are built off of this, rather than the old

@images-path.
For builds and for Storybook runtimes, this variable gets overridden to

point to the right place, ensuring we're accessing images from the right

place.
We're also now ensuring files are built before publishing, avoiding any

bad uploaded builds.
Through this, we should now have proper builds going forward, with paths

referenced correctly.

Built the package and compared to a released build. Verified that the only

changes made were fixes to the images and Spina references.