Make it easy to locally serve docs with all the features #7013
Description
Right now just serving doc/html lets you view the documentation but the interactive features like the search box don't work. I think the files expect the hierarchy of nim-lang.org, but that doesn't match the hierarchy of the repo. There should be a single command to start a local http server hosting the docs with all the bells and whistles.
On a related note, it would be really cool if there was something like nim-lang.org/devel-docs that had a nightly(?) build of the docs from the devel branch.