Create 2025-08-15-terraform-v5.8.4-provider.mdx

[KaydeeDee]

v5.8.4 changelog

Summary

Terraform v5.8.4 release changelog

Documentation checklist

• [ x] Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• [x ] The documentation style guide has been adhered to.
• [x ] If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.