Support pasting content directly instead of pulling it via URL

[rodolfo42]

Sometimes, I have a rather small CSV output that I'd like to throw in charted.

Would be nice to be able to have the source being pasted in via a textarea, perhaps limiting the size to avoid issues.

This could even be disabled in the hosted version to avoid running into space issues in wherever it's hosted now. Instead, it could only be available when running locally or on users' own hardware.

I can give it a shot.