[ext/yaml] add indentation rules configuration

extensions/yaml/language-configuration.json

@@ -23,5 +23,9 @@
 	],
 	"folding": {
 		"offSide": true
+	},
+	"indentationRules": {
+		"increaseIndentPattern": "^\\s*.*(:|-) ?(&\\w+)?(\\{[^}\"']*|\\([^)\"']*)?$",
+		"decreaseIndentPattern": "^\\s+\\}$"
 	}
-}
+}