Add nimble-base prefix to tokens

[rajsite]

Pull Request

🤨 Rationale

This PR addresses the second half of #236 (comment) by adding the prefix nimble-base to the raw tokens defined in ni/tokens.

👩‍💻 Implementation

• Modified the nimble-extensions for the Adobe DSP to add a prefix to the names. Used a workaround as I couldn't see a way to configure a prefix using the DSP itself. I created the following issue for the workaround: Define a prefix for css and scss files AdobeXD/design-system-package-dsp#27
• Only defined the prefix for css and scss files. The rationale being that those are set globally in a page and can conflict. The JS files are modules that are explicitly imported and not globally available so are unlikely to get used accidentally.

🧪 Testing

Just CI builds, no explicit testing.

✅ Checklist

• I have updated the project documentation to reflect my changes or determined no changes are needed. Doc changes will be aligned with Improve documentation for design tokens #231 or after. Won't address in this PR.

[jattasNI]

Under the assumption that this will go in imminently, I updated #231 to use the new naming scheme in the nimble-tokens README.md. Feel free to leave a comment on that PR if you think we should go into more detail about the naming scheme.

[fredvisser]

LGTM - Cool that you were able to find a fairly clean way to extend the existing kebab transform - 👍