Handle BigInt errors when bundling js-math-tools in Vite

Transpilation fails when bundling js-math-tools with Vite because the library uses BigInt in some of its calculations. To fix this, add these settings to the vite.config.js file:

module.exports = {
  build: {
    target: "es2020",
  },

  optimizeDeps: {
    esbuildOptions: {
      target: "es2020",
    },
  },
}

Since this solution was actually found in the SvelteKit GitHub repo's issues list, it may be the case that this solution will work for other bundlers, perhaps with minimal tweaks.

Sources