[menu] Add a reading list with links (#1208)

* [menu] Add a reading list with links

* Review: format and disclosure links

* Fix deploy failure

Author: dizhang168

site/src/pages/components/menu.explainer.mdx

@@ -142,7 +142,7 @@ We should support `<fieldset>` and `<legend>` to help group the menu items toget
 
 We should support specific use cases of interactive elements outside the `<menuitem>`. For example, if the user wants to add an `<input type=search>` element, it should not be wrapped inside a `<menuitem>` and should instead be a sibling of `<menuitem>`s.
 
-<img src="/images/menubar-search-input.png" alt="menubar examples with search input as a sibling of menuitems">
+<img src="/images/menubar-search-input.png" alt="menubar examples with search input as a sibling of menuitems" />
 
 
 ## Questions
@@ -366,7 +366,6 @@ There are ARIA guidelines for the [toolbar](https://www.w3.org/WAI/ARIA/apg/patt
 
 There is a history of attempting to do this in Webkit, for example for a [Touch Bar](https://github.com/whatwg/html/issues/3251). The idea for this is to collect all your "commands" and put them into the macOS menu bar (or expose them some other way). This proposal will not address this yet.
 
-
 ## Examples in code
 
 
@@ -402,3 +401,53 @@ bold.addEventListener("click", () => {
 });
 </script>
 ```
+
+## Reading List
+
+Menus have been heavily discussed, please see below to learn about the existing specification and efforts.
+
+### ARIA guidelines
+- the ARIA [menu role](https://w3c.github.io/aria/#menu)
+- the ARIA [menubar role](https://w3c.github.io/aria/#menubar)
+- the ARIA [menuitem role](https://w3c.github.io/aria/#menuitem)
+- the ARIA [menuitemcheckbox role](https://w3c.github.io/aria/#menuitemcheckbox)
+- the ARIA [menuitemradio role](https://w3c.github.io/aria/#menuitemradio)
+- the [Core AAM mappings](https://www.w3.org/TR/core-aam-1.2/#role-map-menu)
+- the [HTML AAM for &lt;menu>](https://www.w3.org/TR/html-aam-1.0/#el-menu)
+
+### Relevant ARIA issues
+- [ARIA] [Consider allowing combobox to open menus](https://github.com/w3c/aria/issues/2050)
+
+### Relevant Navigation specific issues
+- [ARIA practices] [Clarify Purpose of Menu Navigation](https://github.com/w3c/aria-practices/issues/353)
+- [OpenUI] [Navigation vs menu items use case](https://github.com/openui/open-ui/issues/1193)
+- [ARIA] [Concerning navigation "menus" (open ui related)](https://github.com/w3c/aria/issues/2510)
+
+### APG pattern recommendations (note these are not guidelines)
+- [menu button](https://www.w3.org/WAI/ARIA/apg/patterns/menu-button/)
+- [menubar](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/)
+  - [menubar example](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-editor/)
+  - [menubar navigation example](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-navigation/)
+- [disclosure](https://www.w3.org/WAI/ARIA/apg/patterns/disclosure/)
+  - [disclosure navigation menu example](https://www.w3.org/WAI/ARIA/apg/patterns/disclosure/examples/disclosure-navigation/)
+  - [disclosure navigation menu with top-level links example](https://www.w3.org/WAI/ARIA/apg/patterns/disclosure/examples/disclosure-navigation-hybrid/)
+- [toolbar](https://www.w3.org/WAI/ARIA/apg/patterns/toolbar/)
+
+### HTML specification
+- The [menu element](https://html.spec.whatwg.org/multipage/grouping-content.html#the-menu-element)
+- The [nav element](https://html.spec.whatwg.org/multipage/#the-nav-element)
+
+### HTML specification for previous efforts
+- The [obsoleted menuitem element](https://html.spec.whatwg.org/multipage/obsolete.html#menuitem)
+- The [obsoleted type attribute on menu element](https://html.spec.whatwg.org/multipage/obsolete.html#attr-menu-type)
+
+### Blog posts from accessibility community
+- https://www.scottohara.me/blog/2021/10/21/menu.html
+- https://adrianroselli.com/2017/10/dont-use-aria-menu-roles-for-site-nav.html
+- https://adrianroselli.com/2019/06/link-disclosure-widget-navigation.html
+- https://adrianroselli.com/2023/05/be-careful-using-menu.html
+
+### Blog posts for Design System
+- https://webflow.com/blog/navigation-bar-design
+- https://developer.apple.com/design/human-interface-guidelines/the-menu-bar
+