ADD: formatting rules for json and yaml

Author: GrimLink

.editorconfig

@@ -10,3 +10,9 @@ trim_trailing_whitespace = true
 
 [*.md]
 trim_trailing_whitespace = false
+
+[*.{yml,yaml,json}]
+indent_size = 2
+
+[composer.{json,lock}]
+indent_size = 4