Add "types" to "exports"

When trying to use `fast-check` with TypeScript where  `moduleResolution` is set to `Node12` or `NodeNext` we get the following error:

> Could not find a declaration file for module 'fast-check'. '/home/makeen/q2web/Dev/openapi-codegen/node_modules/fast-check/lib/esm/fast-check.js' implicitly has an 'any' type.

> Try `npm i --save-dev @types/fast-check` if it exists or add a new declaration (.d.ts) file containing `declare module 'fast-check';`ts(7016)

This change fixes the issue.

I think this might be related: microsoft/TypeScript#46334

package.json

@@ -7,6 +7,7 @@
   "exports": {
     ".": {
       "require": "./lib/fast-check.js",
+      "types": "./lib/types/fast-check.d.ts",
       "default": "./lib/esm/fast-check.js"
     }
   },