Remove normalize.css's styling of search inputs

As discussed here: https://github.com/Jermolene/TiddlyWiki5/issues/4984#issuecomment-723169753

test.html

@@ -0,0 +1 @@
+<input value="Something"/>

themes/tiddlywiki/vanilla/base.tid

@@ -53,6 +53,10 @@ $else$
 	-webkit-box-sizing: border-box;
 }
 
+input[type="search"] {
+  outline-offset: initial;
+}
+
 html button {
 	line-height: 1.2;
 	color: <<colour button-foreground>>;