Updated the free frontend GitHub repository v1.3

Updated the public github repository to be the same frontend as demo.netcoresaas.com:

https://github.com/netcoresaas/saas-vuejs-tailwindcss

The strategy is that if a user likes the VueJS + TailwindCSS 2.0 frontend, they can get the .NET backend at netcoresaas.com/pricing.