Add devcontainer and stuff

package.json

@@ -6,13 +6,15 @@
   "main": "index.js",
   "scripts": {
     "build": "rollup -c",
-    "watch": "rollup -c -w"
+    "watch": "rollup -c -w",
+    "serve": "http-server ."
   },
   "author": "",
   "license": "ISC",
   "devDependencies": {
     "@rollup/plugin-node-resolve": "^9.0.0",
     "@rollup/plugin-typescript": "^5.0.2",
+    "http-server": "^0.12.3",
     "rollup": "^2.26.4",
     "tslib": "^2.0.1",
     "typescript": "^4.0.2"