Add GitHub action infrastructure.

package.json

@@ -0,0 +1,50 @@
+{
+  "name": "setup-graalvm",
+  "version": "1.0.0",
+  "private": true,
+  "description": "GitHub Action for GraalVM",
+  "main": "lib/main.js",
+  "scripts": {
+    "build": "tsc",
+    "format": "prettier --write '**/*.ts'",
+    "format-check": "prettier --check '**/*.ts'",
+    "lint": "eslint src/**/*.ts",
+    "package": "ncc build --source-map --license licenses.txt",
+    "test": "jest",
+    "all": "npm run build && npm run format && npm run lint && npm run package && npm test"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/graalvm/setup-graalvm.git"
+  },
+  "keywords": [
+    "graalvm",
+    "native image",
+    "actions",
+    "setup"
+  ],
+  "author": "GraalVM Developers",
+  "license": "UPL",
+  "dependencies": {
+    "@actions/core": "^1.6.0",
+    "@actions/exec": "^1.1.0",
+    "@actions/http-client": "^1.0.11",
+    "@actions/io": "^1.1.1",
+    "@actions/tool-cache": "^1.7.1",
+    "@octokit/core": "^3.5.1",
+    "@octokit/types": "^6.34.0"
+  },
+  "devDependencies": {
+    "@types/node": "^17.0.6",
+    "@typescript-eslint/parser": "^5.8.1",
+    "@vercel/ncc": "^0.33.1",
+    "eslint": "^8.6.0",
+    "eslint-plugin-github": "^4.3.5",
+    "eslint-plugin-jest": "^25.3.4",
+    "jest": "^27.4.5",
+    "js-yaml": "^4.1.0",
+    "prettier": "2.5.1",
+    "ts-jest": "^27.1.2",
+    "typescript": "^4.5.4"
+  }
+}