compile artifacts before packing and generate typechains on postinstall.

Author: muzam

package.json

@@ -4,7 +4,8 @@
   "description": "Smart contracts for vanilladefi.com",
   "main": "./typechain/vanilla_v1.1/index.ts",
   "scripts": {
-    "postinstall": "npm run compile:sol & npm run generate:typechain-wo-test",
+    "prepack": "npm run compile:sol",
+    "postinstall": "npm run generate:typechain-wo-test",
     "test": "npm run generate:test-types && npx hardhat test",
     "format:js": "eslint --fix test/ utils/ hardhat/ deploy/",
     "format:sol": "prettier --write contracts/",