Ugh, we need to write out a TypeScript file instead of importing the JSON directly because otherwise the TS compiler will spend an inordinate amount of time doing type inference, which massively slows down type-checking (especially in IDEs and such).
The TS file actually uses `JSON.parse` on a stringified version of the JSON instead of just inlining the JSON itself because [apparently it's much faster][1].
[1]: https://www.bram.us/2019/11/25/faster-javascript-apps-with-json-parse/
This adds an extremely simple Mandala page (for #24) with a single circle Mandala comprised of several eyes. The symbol style is configurable, but parameters for the actual Mandala are not (yet).
Doing this also involved factoring out a `<SvgTransforms>` component, which makes setting up SVG transforms a bit easier.
Also moved `getSymbol` of `creature-page.tsx` and into `svg-vocabulary.tsx`, with the new name `getSvgSymbol`.