Documentation: Add links to release tarball index pages (#1802)

Updating `RELEASES.md` to account for #1406

Author: jayhawk-commits

RELEASES.md

@@ -375,12 +375,11 @@ wrapper Python wheels or utility scripts.
 ### Installing release tarballs
 
 Release tarballs are automatically uploaded to AWS S3 buckets.
-The S3 buckets do not yet have index pages.
 
-| S3 bucket                                                                    | Description                                       |
-| ---------------------------------------------------------------------------- | ------------------------------------------------- |
-| [therock-nightly-tarball](https://therock-nightly-tarball.s3.amazonaws.com/) | Nightly builds from the `main` branch             |
-| [therock-dev-tarball](https://therock-dev-tarball.s3.amazonaws.com/)         | ⚠️ Development builds from project maintainers ⚠️ |
+| S3 bucket                                                                              | Description                                       |
+| -------------------------------------------------------------------------------------- | ------------------------------------------------- |
+| [therock-nightly-tarball](https://therock-nightly-tarball.s3.amazonaws.com/index.html) | Nightly builds from the `main` branch             |
+| [therock-dev-tarball](https://therock-dev-tarball.s3.amazonaws.com/index.html)         | ⚠️ Development builds from project maintainers ⚠️ |
 
 After downloading, simply extract the release tarball into place: