Make the help button look more like the rest

Author: notriddle

src/librustdoc/html/static/css/rustdoc.css

@@ -1800,7 +1800,7 @@ button#toggle-all-docs:before {
 	/* Question mark with circle */
 	content: url('data:image/svg+xml,<svg width="18" height="18" viewBox="0 0 12 12" \
 	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg" fill="none">\
-	<circle r="5.5" cx="6" cy="6" stroke-width="1" stroke="black"/>\
+	<circle r="5.25" cx="6" cy="6" stroke-width="1.25" stroke="black"/>\
 	<text x="4.25" y="9" style="font:8px sans-serif;font-weight:1000" fill="black">?</text></svg>');
 	width: 18px;
 	height: 18px;