Convert TOML front matter to YAML (#49690)

Signed-off-by: Jack Baldry <jack.baldry@grafana.com>

docs/sources/developers/http_api/preferences.md

@@ -1,9 +1,16 @@
-+++
-aliases = ["/docs/grafana/latest/developers/http_api/preferences/", "/docs/grafana/latest/http_api/preferences/"]
-description = "Grafana HTTP API"
-keywords = ["grafana", "http", "documentation", "api", "preferences"]
-title = "HTTP Preferences API "
-+++
+---
+aliases:
+  - /docs/grafana/latest/developers/http_api/preferences/
+  - /docs/grafana/latest/http_api/preferences/
+description: Grafana HTTP API
+keywords:
+  - grafana
+  - http
+  - documentation
+  - api
+  - preferences
+title: 'HTTP Preferences API '
+---
 
 # User and Org Preferences API