Docs: Adding DFW status page (#752)

Author: the2hill

docs/api-status.md

@@ -11,3 +11,5 @@ hide:
 ## :octicons-quote-24: Available Regions
 
 - [SJC](https://status.api.sjc3.rackspacecloud.com/) ![status](https://img.shields.io/endpoint?url=https%3A%2F%2Fraw.githubusercontent.com%2Frackerlabs%2Frs-flex-uptime%2Frefs%2Fheads%2Fmaster%2Fstatus.json)
+
+- [DFW](https://status.api.dfw3.rackspacecloud.com/) ![status](https://img.shields.io/endpoint?url=https%3A%2F%2Fraw.githubusercontent.com%2Fthe2hill%2Frs-flex-uptime-dfw%2Frefs%2Fheads%2Fmaster%2Fstatus.json)