Update gitignore, add build:dev command

.gitignore

@@ -1,6 +1,5 @@
 .DS_Store
 node_modules
-/dist
 
 # local env files
 .env.local
@@ -27,3 +26,4 @@ test/unit/coverage
 docs/gitbook/_book
 docs/node_modules
 site
+dev/dist

package.json

@@ -5,6 +5,7 @@
   "scripts": {
     "serve": "vue-cli-service serve ./dev/dev.js",
     "build": "vue-cli-service build --target lib ./src/index.js",
+    "build:dev": "vue-cli-service build --dest ./dev/dist ./dev/dev.js ",
     "lint": "vue-cli-service lint",
     "test:unit": "vue-cli-service test:unit"
   },