Rearrange z-indexing within the Navigation & SidebarLayout to fix overlay glitch with the docson component

Author: ryyppy

components/Navigation.re

@@ -471,7 +471,7 @@ let make = (~fixed=true, ~overlayState: (bool, (bool => bool) => unit)) => {
     [||],
   );
 
-  let fixedNav = fixed ? "fixed z-20 top-0" : "";
+  let fixedNav = fixed ? "fixed z-30 top-0" : "";
 
   <nav
     ref={ReactDOMRe.Ref.domRef(outerRef)}
@@ -587,7 +587,7 @@ let make = (~fixed=true, ~overlayState: (bool, (bool => bool) => unit)) => {
       style={Style.make(~minWidth, ~top="4.5rem", ())}
       className={
         (isOverlayOpen ? "flex" : "hidden")
-        ++ " sm:hidden flex-col fixed top-0 left-0 h-full w-full z-20 sm:w-9/12 bg-gray-100 sm:h-auto sm:flex sm:relative sm:flex-row sm:justify-between"
+        ++ " sm:hidden flex-col fixed top-0 left-0 h-full w-full z-30 sm:w-9/12 bg-gray-100 sm:h-auto sm:flex sm:relative sm:flex-row sm:justify-between"
       }>
       <MobileNav route />
     </div>

layouts/SidebarLayout.re

@@ -164,7 +164,7 @@ module Sidebar = {
       <div
         id="sidebar"
         className={
-          (isOpen ? "fixed w-full left-0 h-full z-10 min-w-320" : "hidden ")
+          (isOpen ? "fixed w-full left-0 h-full z-20 min-w-320" : "hidden ")
           ++ " md:block md:w-48 md:-ml-4 lg:w-1/4 md:h-auto md:relative overflow-y-visible bg-white md:relative"
         }
         style={Style.make(~minWidth="12.9375rem", ())}>
@@ -306,7 +306,7 @@ let make =
               <main
                 className="px-6 w-full md:ml-12 md:mx-8 pt-16 md:mt-2 md:pt-24 mb-32 text-lg max-w-705">
                 <div
-                  className="fixed border-b shadow top-18 left-0 pl-4 bg-white w-full py-4 md:relative md:border-none md:shadow-none md:p-0 md:top-auto flex items-center">
+                  className="z-10 fixed border-b shadow top-18 left-0 pl-4 bg-white w-full py-4 md:relative md:border-none md:shadow-none md:p-0 md:top-auto flex items-center">
                   <MobileDrawerButton
                     hidden=isNavOpen
                     onClick={evt => {