use up to date scripts from the extension cookiecutter

Previously watch mode would not actually watch for changes

Author: ianhi

package.json

@@ -21,20 +21,25 @@
     "url": "https://github.com/jupyter-widgets/jupyterlab-sidecar"
   },
   "scripts": {
-    "build": "jlpm run build:lib && jlpm run build:labextension",
+    "build": "jlpm run build:lib && jlpm run build:labextension:dev",
+    "build:prod": "jlpm run build:lib && jlpm run build:labextension",
     "build:labextension": "jupyter labextension build .",
+    "build:labextension:dev": "jupyter labextension build --development True .",
     "build:lib": "tsc",
-    "clean": "jlpm run clean:lib && jlpm run clean:labextension",
-    "clean:lib": "rimraf lib",
+    "clean": "jlpm run clean:lib",
+    "clean:lib": "rimraf lib tsconfig.tsbuildinfo",
     "clean:labextension": "rimraf sidecar/labextension",
-    "prepare": "jlpm run build",
+    "clean:all": "jlpm run clean:lib && jlpm run clean:labextension",
     "test": "jlpm run test:firefox",
     "test:chrome": "karma start --browsers=Chrome tests/karma.conf.js",
     "test:debug": "karma start --browsers=Chrome --singleRun=false --debug=true tests/karma.conf.js",
     "test:firefox": "karma start --browsers=Firefox tests/karma.conf.js",
     "test:ie": "karma start --browsers=IE tests/karma.conf.js",
-    "watch": "npm-run-all -p watch:*",
-    "watch:lib": "tsc"
+    "install:extension": "jupyter labextension develop --overwrite .",
+    "prepare": "jlpm run clean && jlpm run build:prod",
+    "watch": "run-p watch:src watch:labextension",
+    "watch:src": "tsc -w",
+    "watch:labextension": "jupyter labextension watch ."
   },
   "dependencies": {
     "@jupyter-widgets/base": "^4.0.0",