Set up the new website

[CircuitCoder]

Including:

• [x] Setup the download server
• [x] Setup the documentation site
• [x] Update the documentation on GitHub and WeChat

[CircuitCoder]

On the matter of download server:

• [x] Setup minio as its backend
• [ ] Probably use Aliyun CDN as a cache if the traffic is massive.
• [x] Set environment variables within CI settings, instead of config files, for better portability.

[CircuitCoder]

On the matter of the documentation site:

• [x] Plan to use https://github.com/vuejs/vuepress as its generator.
• [x] Custom index written by hand, hosted under https://github.com/CircuitCoder/easymun.net

[CircuitCoder]

I'm going to close this for now. Further enhancements such as monitoring for network traffic and server loads will take place if necessary.