fix: publishing needs readme to be relative to the project

[keplervital]

No description provided.

[peterpeterparker]

I guess the issue arises from my recent PR #31. For the record, I tested it from the root directory by running the command cargo doc --package canfund --open. Apologies if it caused any issues — I didn't know the library was not published from the root.

[keplervital]

cargo doc --package canfund --open

The above works, but cargo publish from the root is the one that fails, it seems it fails with the cargo package command, you can try it with cargo publish --package canfund --dry-run