AVRO-3193: Add Rust Checks to Readme

[kojiromike]

The README has not been updated since the adoption of the Rust component. Even though the rust checks aren't passing, having them present will make it clear to people exploring the repo in GitHub that there is a rust implementation, and provides guidance about what needs to be addressed.

Jira

• Addresses AVRO-3193
• PR title tags the Jira issue
• Adds no new dependency

Tests

• N/A

Commits

• Commits all reference the Jira issue in their subject lines.
• Commits follow the guidelines from "How to write a good git commit message":

Documentation

• In case of new functionality, my PR adds documentation that describes how to use it.