feat(dart): add indents

queries/dart/indents.scm

@@ -0,0 +1,27 @@
+[
+  (class_body)
+  (function_body)
+  (function_expression_body)
+  (declaration (initializers))
+  (switch_block)
+  (if_statement)
+  (formal_parameter_list)
+  (formal_parameter)
+  (list_literal)
+  (return_statement)
+  (arguments)
+] @indent
+
+[
+  "("
+  ")"
+  "{"
+  "}"
+  "["
+  "]"
+] @branch
+
+; this one is for dedenting the else block
+(if_statement (block) @branch)
+
+(comment) @ignore