Make it possible to use as NPM package

package.json

@@ -6,11 +6,14 @@
   "repository": "[email protected]:jmpinit/p5.axidraw.git",
   "author": "Owen Trueblood <[email protected]>",
   "license": "MIT",
+  "main": "dist/p5.axidraw.js",
   "scripts": {
     "build": "node node_modules/webpack-cli/bin/cli.js --config webpack.prod.js",
     "watch": "node node_modules/webpack-cli/bin/cli.js watch --config webpack.dev.js",
-    "docs": "node node_modules/documentation/bin/documentation.js build -f html -o docs src/index.js"
+    "docs": "node node_modules/documentation/bin/documentation.js build -f html -o docs src/index.js",
+    "prepublishOnly": "yarn && yarn build"
   },
+  "files": ["dist/"],
   "dependencies": {
     "ebb-control": "git+https://github.com/jmpinit/ebb-control.git#47e737aac4d898f6becabdb526c64876c12ad989"
   },