Improve file list display

Author: GuillaumeGomez

src/librustdoc/html/static/rustdoc.css

@@ -1570,5 +1570,6 @@ div.name::before {
 }
 div.name.expand::before {
 	transform: rotate(90deg);
-	left: -14px;
+	left: -15px;
+	top: 2px;
 }

src/librustdoc/html/static/source-script.js

@@ -94,7 +94,7 @@ function createSidebarToggle() {
     inner1.style.position = "relative";
 
     var inner2 = document.createElement("div");
-    inner2.style.marginTop = "-2px";
+    inner2.style.paddingTop = "3px";
     if (getCurrentValue("rustdoc-source-sidebar-show") === "true") {
         inner2.innerText = "<";
     } else {