Fix Airbnb Chronon repo link (#746)

## Summary

Add `https://` protocol to open link to
`https://github.com/airbnb/chronon` and not
`https://github.com/zipline-ai/chronon/blob/main/github.com/airbnb/chronon`

## Checklist
- [ ] Added Unit Tests
- [ ] Covered by existing CI
- [ ] Integration tested
- [ ] Documentation update


<!-- av pr metadata
This information is embedded by the av CLI when creating PRs to track
the status of stacks when using Aviator. Please do not delete or edit
this section of the PR.
```
{"parent":"main","parentHead":"","trunk":"main"}
```
-->


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Documentation**
- Updated the README to include the "https://" protocol in the GitHub
URL for Airbnb's Chronon repository.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Sean Lynch <[email protected]>

Author: sean-zlai

README.md

@@ -1,4 +1,4 @@
-> DISCLAIMER: This is a fork of [Airbnb's Chronon repo](github.com/airbnb/chronon) with the same Apache-2 license.
+> DISCLAIMER: This is a fork of [Airbnb's Chronon repo](https://github.com/airbnb/chronon) with the same Apache-2 license.
 > 
 > ### What are the main differences?
 >   - Additional Connectors: BigQuery, Hudi, Glue, Iceberg, BigTable, Dynamo, Pub/Sub etc.