User self domain name.

[bakamake]

No description provided.

[EchoZap]

我也希望可以支持用户自己的域名，甚至说所有的设置用户都可以掌握在自己手里

[mazzzystar]

Thanks, setting up a custom domain seems pretty tricky. Hopefully someone more skilled can help me fulfill this requirement.

[metrue]

I made a very shabby pull request weeks before, it works for my domain https://iiiii.li deployed on vercel.com, feel free to comment, hopefully it's can be part of the tinymind.
#25