add typecheck as npm cmd, pre-commit hook

Author: lukasvice

.githooks/pre-commit

@@ -4,3 +4,4 @@ set -e
 set -o pipefail
 
 npm run lint
+npm run typecheck

package.json

@@ -17,6 +17,7 @@
     "build": "tsc",
     "lint": "eslint --ext js,ts,tsx src",
     "lint:fix": "npm run lint -- --fix",
+    "typecheck": "tsc --noEmit",
     "test": "jest --config jestconfig.json --passWithNoTests",
     "prepare": "npm run build",
     "prepublishOnly": "npm run test && npm run lint",