Add index.d.ts to allow esm imports

Author: Gideonnn

package.json

@@ -6,6 +6,7 @@
     "build": "node scripts/build.js",
     "server": "node scripts/server.js"
   },
+  "typings": "./dist/index.d.ts",
   "exports": {
     ".": [
       "./dist/index.js"

src/index.d.ts

@@ -0,0 +1,5 @@
+export { default as abis } from '@nexusmutual/sdk/dist/contracts/abis';
+export { default as addresses } from '@nexusmutual/sdk/dist/contracts/addresses.json';
+export { default as productTypes } from '@nexusmutual/sdk/dist/products/product-types.json';
+export { default as products } from '@nexusmutual/sdk/dist/products/products.json';
+export { default as logos } from '@nexusmutual/sdk/dist/products/product-logos.json';