[Feature Request] Custom Source

I would love to be able to embed a contract abi source in the URL params like `eth95.dev?abi=` and the page makes a single request for the abi at that source. This would be helpful for scenarios where I want to give someone a link and then following the link gives them everything they need to interact with a contract. I end up manually walking lots of folks through the precursor steps when they're not quite blockchain natives.

For reference, [Remix](https://remix-ide.readthedocs.io/en/latest/locations.html) allows a user to insert a gist, filepath, or even the raw source code in a query param.