If you're doing this as a business, you should consider how you think this is different from e.g. Figma (for designers/PMs) or Framer (for design-implemented-as-actual-usable-component-on-a-low-code-site). What you're describing sounds very similar to Figma's developer mode, at least framed the way you frame it here. Is the idea that, say, the design files are loaded as CSS or React components or whatever directly into your site, rather than being copied or imported?
(If this is just a personal project, disregard! But "quit my job" makes me think you're thinking of this as a business.)
(If this is just a personal project, disregard! But "quit my job" makes me think you're thinking of this as a business.)