Feature Request: Remote files

[Umaaz]

I have recently come across the use case where I need to include a markdown file that is in another git repo. What is your opinion on making it possible to do this.

As an example if could be:

{! https://raw.githubusercontent.com/<user>/<repo>/<branch>/docs/some_file.md !}

It could detect the urls easily enough download to a temp file and then include as normal.