chore: setup monorepo using preconstruct

packages/core/src/custom.d.ts

@@ -0,0 +1,17 @@
+declare module '*.css' {
+  const content: { [className: string]: string };
+  export default content;
+}
+
+interface SvgrComponent extends React.FunctionComponent<React.SVGAttributes<SVGElement>> {}
+
+declare module '*.svg' {
+  const svgUrl: string;
+  const svgComponent: SvgrComponent;
+  export default svgUrl;
+  export { svgComponent as ReactComponent };
+}
+
+declare var __REACT_FLOW_VERSION__: string;
+declare var __ENV__: string;
+declare var __INJECT_STYLES__: boolean;