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

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

@@ -905,6 +905,8 @@ both the code example and the line numbers, so we need to remove the radius in t
 .docblock h6 { font-size: 0.875rem; }
 
 .docblock {
+	margin-top: .75em;
+	margin-bottom: .75em;
 	margin-left: 24px;
 	position: relative;
 }