feat(techdocs): add addon settings location

Signed-off-by: Camila Belo <camilaibs@gmail.com>

docs/features/techdocs/addons.md

@@ -35,6 +35,8 @@ representative of physical spaces in the TechDocs UI:
   line as the title.
 - `Subheader`: For Addons that sit below the header but above all content.
   This is a great location for tooling/configuration of TechDocs display.
+- `Settings`: These addons are items added to the settings menu list and are designed to make
+  the reader experience customizable, for example accessibility options.
 - `PrimarySidebar`: Left of the content, above of the navigation.
 - `SecondarySidebar`: Right of the content, above the table of contents.
 - `Content`: A special location intended for Addons which augment the

plugins/techdocs-react/src/types.ts

@@ -53,6 +53,12 @@ export const TechDocsAddonLocations = Object.freeze({
    */
   Subheader: 'Subheader',
 
+  /**
+   * These addons are items added to the settings menu list and are designed to make
+   * the reader experience customizable, for example accessibility options
+   */
+  Settings: 'Settings',
+
   /**
    * These addons appear left of the content and above the navigation.
    */