Idea: Loading large code snippets from arbitrary urls

First, some context: I'm writing a blog post on which I want to provide playground links for all code snippets. Using gist.github.com for this sort of use case would be very annoying to keep up to date when I change the snippets. I have been successfully using urls with embedded code, but finally hit 414 Request-URI Too Large with this snippet.

My first thought on a way to support this usecase was extending play.rust-lang.org to load code from arbitrary urls instead of only supporting gist.github.com. For example it could take a link like

https://play.rust-lang.org/?version=nightly&edition=2018&file=https%3A%2F%2Fnemo157.com%2Ffoo.rs

and load the specified file client-side.

As far as I can tell there should be no additional security issues with this. The code would just be performing a fetch for the file and loading the content into the text box, any potential attack would be the same as when it's loading from a gist.

I'm willing to implement this, just wanted to get feedback on whether you'd accept this approach/have other ideas on a way to support my usecase before spending time on it.

The issue does not name files or tests; start by locating the existing client-side gist loading path and its URL parsing. The requested behavior is to fetch code from an arbitrary URL and load it into the playground text box, while confirming the proposed approach is acceptable.