Export compiled artifacts for usage in other projects

We will export compiled contracts artifacts to use them in other
projects.

Author: nkuba

package.json

@@ -24,7 +24,7 @@
     "test": "hardhat test",
     "test:system": "NODE_ENV=system-test hardhat test ./test/system/*.test.js",
     "prepublishOnly": "./scripts/prepare-artifacts.sh --network $npm_config_network",
-    "postinstall": "tsc -p tsconfig.export.json"
+    "postinstall": "tsc -p tsconfig.export.json && hardhat export-artifacts export/artifacts"
   },
   "devDependencies": {
     "@keep-network/hardhat-helpers": "^0.4.1-pre.2",

tsconfig.json

@@ -1,6 +1,4 @@
 {
-  "files": [
-    "./hardhat.config.ts",
-  ],
+  "files": ["./hardhat.config.ts"],
   "include": ["./deploy"]
 }