fix(rustdoc): add space between struct fields and their descriptions

Author: ismailarilik

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

@@ -230,6 +230,12 @@ h4.code-header {
 	padding: 0;
 	white-space: pre-wrap;
 }
+.structfield {
+	margin-block-start: .6em;
+	margin-block-end: .6em;
+	margin-inline-start: 0px;
+	margin-inline-end: 0px;
+}
 
 #crate-search,
 h1, h2, h3, h4, h5, h6,