added s3dns as bucket auditing tool

README.md

@@ -230,6 +230,7 @@ Do you want to contribute to this list? Feel free to send a PR and make sure you
 | **[festin](https://github.com/cr0hn/festin)** | S3 bucket weakness discovery | [![stars](https://badgen.net/github/stars/cr0hn/festin)](https://badgen.net/github/stars/cr0hn/festin) | [![contributors](https://badgen.net/github/contributors/cr0hn/festin)](https://badgen.net/github/contributors/cr0hn/festin) [![watchers](https://badgen.net/github/watchers/cr0hn/festin)](https://badgen.net/github/watchers/cr0hn/festin) [![last-commit](https://badgen.net/github/last-commit/cr0hn/festin)](https://badgen.net/github/last-commit/cr0hn/festin) [![open-issues](https://badgen.net/github/open-issues/cr0hn/festin)](https://badgen.net/github/open-issues/cr0hn/festin) [![closed-issues](https://badgen.net/github/closed-issues/cr0hn/festin)](https://badgen.net/github/closed-issues/cr0hn/festin) |
 | **[S3Insights](https://github.com/kurmiashish/S3Insights)** | a platform for efficiently deriving security insights about S3 data through metadata analysis  | [![stars](https://badgen.net/github/stars/kurmiashish/S3Insights)](https://badgen.net/github/stars/kurmiashish/S3Insights) | [![contributors](https://badgen.net/github/contributors/kurmiashish/S3Insights)](https://badgen.net/github/contributors/kurmiashish/S3Insights) [![watchers](https://badgen.net/github/watchers/kurmiashish/S3Insights)](https://badgen.net/github/watchers/kurmiashish/S3Insights) [![last-commit](https://badgen.net/github/last-commit/kurmiashish/S3Insights)](https://badgen.net/github/last-commit/kurmiashish/S3Insights) [![open-issues](https://badgen.net/github/open-issues/kurmiashish/S3Insights)](https://badgen.net/github/open-issues/kurmiashish/S3Insights) [![closed-issues](https://badgen.net/github/closed-issues/kurmiashish/S3Insights)](https://badgen.net/github/closed-issues/kurmiashish/S3Insights) |
 | **[s3_objects_check](https://github.com/nccgroup/s3_objects_check)** | Whitebox evaluation of effective S3 object permissions, to identify publicly accessible files.  | [![stars](https://badgen.net/github/stars/nccgroup/s3_objects_check)](https://badgen.net/github/stars/nccgroup/s3_objects_check) | [![contributors](https://badgen.net/github/contributors/nccgroup/s3_objects_check)](https://badgen.net/github/contributors/nccgroup/s3_objects_check) [![watchers](https://badgen.net/github/watchers/nccgroup/s3_objects_check)](https://badgen.net/github/watchers/nccgroup/s3_objects_check) [![last-commit](https://badgen.net/github/last-commit/nccgroup/s3_objects_check)](https://badgen.net/github/last-commit/nccgroup/s3_objects_check) [![open-issues](https://badgen.net/github/open-issues/nccgroup/s3_objects_check)](https://badgen.net/github/open-issues/nccgroup/s3_objects_check) [![closed-issues](https://badgen.net/github/closed-issues/nccgroup/s3_objects_check)](https://badgen.net/github/closed-issues/nccgroup/s3_objects_check) |
+| **[s3dns](https://github.com/olizimmermann/s3dns)** | Passive DNS-based discovery of S3 (and other cloud) buckets by resolving CNAMEs and IPs during recon—ideal for stealthy and early identification of cloud storage exposures | [![stars](https://badgen.net/github/stars/olizimmermann/s3dns)](https://badgen.net/github/stars/olizimmermann/s3dns) | [![contributors](https://badgen.net/github/contributors/nccgroup/s3_objects_check)](https://badgen.net/github/contributors/olizimmermann/s3dns) [![watchers](https://badgen.net/github/watchers/olizimmermann/s3dns)](https://badgen.net/github/watchers/olizimmermann/s3dns) [![last-commit](https://badgen.net/github/last-commit/olizimmermann/s3dns)](https://badgen.net/github/last-commit/olizimmermann/s3dns) [![open-issues](https://badgen.net/github/open-issues/olizimmermann/s3dns)](https://badgen.net/github/open-issues/olizimmermann/s3dns) [![closed-issues](https://badgen.net/github/closed-issues/olizimmermann/s3dns)](https://badgen.net/github/closed-issues/olizimmermann/s3dns) |
 
 ## Training
 | Name | Description | Popularity | Metadata |