Need to add support for `dotFiles` in docsify serve

[dolanmiu]

Can there be an option to allow dot files in docsify serve?

E.g. .prettierrc.yaml.

i am trying to embed this file, and it is failing:

[.prettierrc.yaml](.prettierrc.yaml ":include")

Cannot GET /guides/.prettierrc.yaml

express option to expose:

https://github.com/expressjs/serve-static#dotfiles