fix: standardize on file extension .yaml instead of a mix of yml and yaml

bmad-core/agent-teams/team-all.yaml

@@ -0,0 +1,14 @@
+bundle:
+  name: Team All
+  icon: 👥
+  description: Includes every core system agent.
+agents:
+  - bmad-orchestrator
+  - '*'
+workflows:
+  - brownfield-fullstack
+  - brownfield-service
+  - brownfield-ui
+  - greenfield-fullstack
+  - greenfield-service
+  - greenfield-ui