Update to latest automerge-rs

[atifsyedali]

The current Rust version is 0.5.11, and the one being used in this repo is 0.5.0. Was wondering if there have been any significant changes since, including any additions or changes to API?

[ConradIrwin]

Looks like the main big change was stuff for rich text documents: https://github.com/automerge/automerge/blob/main/rust/CHANGELOG.md.

I'll try and find time to update anyway though as there are a number of bug fixes we should acquire even if we don't expose the new APIs immediately.

[gedw99]

I would like to also see this updated and try to stay synced with the rust code.

its a fantastic golang package

[atifsyedali]

Any updates?