Refactor watch

package.json

@@ -20,10 +20,9 @@
       "build:umd:fullpath": "env OUT=uppy-fp.js ./bin/build-umd --full-paths",
       "build:umd:min": "./bin/build-umd",
       "build:umd": "./bin/build-umd && ./bin/build-umd-locale",
-    "watch": "parallelshell 'npm run watch:all' 'npm run web:preview'",
-      "watch:all": "nodemon --watch src --ext scss,js -x 'npm run build:umd && npm run build:css && node website/update.js'",
+    "watch": "parallelshell 'npm run watch:js' 'npm run watch:css' && node website/update.js",
       "watch:fast": "parallelshell 'npm run watch:css' 'npm run web:preview'",
-      "watch:js": "nodemon --watch src --ext js -x 'npm run build && node website/update.js'",
+      "watch:js": "nodemon --watch src --ext js -x 'npm run build:umd && node website/update.js'",
       "watch:css": "nodemon --watch src --ext scss -x 'npm run build:css && node website/update.js'",
     "web": "npm run web:install && npm run web:clean && npm run web:build",
       "web:preview": "cd website && parallelshell 'node build-examples.js watch' './node_modules/.bin/hexo server'",

website/src/guide/contributing.md

@@ -31,7 +31,7 @@ It's recommended to exclude `./website/public/` from your editor if you want eff
 For local previews on http://127.0.0.1:4000 type:
 
 ```bash
-npm run watch:all
+npm start
 ```
 
 This will watch the website, as well as Uppy, as the examples, and rebuild everything and refresh your browser as files change.