added 'serve' npm script

package.json

@@ -21,6 +21,7 @@
     "watch-tsc": "tsc -watch",
     "watch-extra": "cpx \"src/**/*.{scss,woff,woff2,ttf,otf,eot,svg,html}\" lib/ --watch",
     "watch-webpack": "webpack -w --mode development --display minimal",
+    "serve": "http-server -p 1338",
     "model-server": "node lib/servers/model/server.js",
     "model-server-watch": "nodemon --watch lib lib/servers/model/server.js",
     "preversion": "npm run test",
@@ -72,6 +73,7 @@
     "graphql-code-generator": "^0.18.2",
     "graphql-codegen-time": "^0.18.2",
     "graphql-codegen-typescript-template": "^0.18.2",
+    "http-server": "^0.11.1",
     "jest": "^24.9.0",
     "jest-raw-loader": "^1.0.1",
     "mini-css-extract-plugin": "^0.8.0",