don't remove redundant attributes on visible elements

lib/single-file/htmlnano.js

@@ -102,12 +102,6 @@ this.htmlnano = this.htmlnano || (() => {
 		"form": {
 			"method": "get"
 		},
-		"input": {
-			"type": "text"
-		},
-		"button": {
-			"type": "submit"
-		},
 		"script": {
 			"language": "javascript",
 			"type": "text/javascript",