Overlay documentation fixes (#2221)

* Add/remove missing/nonexisting props

* Add AnchoredOverlay in the navigation

* Add wicked-otters-warn changeset

.changeset/wicked-otters-warn.md

@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+Overlay documentation fixes

docs/content/Overlay.mdx

@@ -72,23 +72,13 @@ See the W3C accessibility recommendations for modals [here](https://www.w3.org/T
 
 ## Positioning
 
-`Overlay` renders its `children` within a div positioned absolutely within a portal within the default portal root. The overlay will not update its positioning if the portal root's positioning changes (e.g., if the portal root is statically positioned after some DOM element that dynamically resizes). You may consider [customizing the portal or specifying a different portal root](/Portal#customizing-the-portal-root) to achieve different positioning behavior.
+`Overlay` renders its `children` within a div positioned absolutely within a portal within the default portal root. The overlay will not update its positioning if the portal root's positioning changes (e.g., if the portal root is statically positioned after some DOM element that dynamically resizes). You may consider using the [AnchoredOverlay](/AnchoredOverlay) component or [customizing the portal root](/Portal#customizing-the-portal-root) to achieve different positioning behavior.
 
 ## Props
 
 ### Overlay
 
 <PropsTable>
-  <PropsTableRow
-    required
-    name="anchorRef"
-    type="React.RefObject<HTMLElement>"
-    description={
-      <>
-        Element the <InlineCode>Overlay</InlineCode> should be anchored to.
-      </>
-    }
-  />
   <PropsTableRow
     required
     name="returnFocusRef"
@@ -182,6 +172,23 @@ See the W3C accessibility recommendations for modals [here](https://www.w3.org/T
       </>
     }
   />
+  <PropsTableRow
+    name="maxHeight"
+    type={`| 'xsmall'
+| 'small'
+| 'medium'
+| 'large'
+| 'xlarge'`}
+    description={
+      <>
+        Sets the maximum height of the <InlineCode>Overlay</InlineCode>, pick from our set list of heights.
+        <InlineCode>xsmall</InlineCode> corresponds to <InlineCode>192px</InlineCode>, <InlineCode>small</InlineCode> corresponds
+        to <InlineCode>256px</InlineCode>, <InlineCode>medium</InlineCode> corresponds to <InlineCode>320px</InlineCode>,{' '}
+        <InlineCode>large</InlineCode> corresponds to <InlineCode>432px</InlineCode>, <InlineCode>xlarge</InlineCode> corresponds
+        to <InlineCode>600px</InlineCode>.
+      </>
+    }
+  />
   <PropsTableRow
     name="visibility"
     type={`| 'visible' 

docs/src/@primer/gatsby-theme-doctocat/nav.yml

@@ -38,6 +38,8 @@
       url: /ActionList
     - title: ActionMenu
       url: /ActionMenu
+    - title: AnchoredOverlay
+      url: /AnchoredOverlay
     - title: Autocomplete
       url: /Autocomplete
     - title: Avatar