Regenerated package-lock.json

The `package-lock.json` was hanging onto old dependencies (some wish security vulterabilities!) even though the parent dependencies had long since been updated.

Notably, this was true of several issues with `cssnano`'s dependency on `dot-prop`. While `npm audit fix` removed these, it did so by leaving `css-nano` in an unusable state.

Given this, I deleted `package-lock.json` and then regenerated it using `npm i --package-lock-only`. This regenerated the file, while removing a _lot_ of old dependencies.

Author: JeremyCaney