feat: replace StudioFooter with StudioFooterSlot (#1729)

src/plugin-slots/README.md

@@ -9,3 +9,6 @@
 ## Course Unit page
 
 * [`course_unit_header_actions_slot`](./CourseUnitHeaderActionsSlot/)
+
+## Footer Slot
+* [`studio_footer_slot`](./StudioFooterSlot/)

src/plugin-slots/StudioFooterSlot/README.md

@@ -0,0 +1,50 @@
+# Studio Footer Slot
+
+### Slot ID: `studio_footer_slot`
+
+## Description
+
+This slot is used to replace/modify/hide the footer.
+
+The implementation of the `StudioFooterSlot` component lives in [the `frontend-slot-footer` repository](https://github.com/openedx/frontend-slot-footer/).
+
+## Example
+
+The following `env.config.jsx` will replace the default footer.
+
+![Screenshot of Default Studio Footer](./images/default_studio_footer.png)
+
+with a simple custom footer
+
+![Screenshot of Custom Footer](./images/custom_footer.png)
+
+```jsx
+import { DIRECT_PLUGIN, PLUGIN_OPERATIONS } from '@openedx/frontend-plugin-framework';
+
+const config = {
+  pluginSlots: {
+    studio_footer_slot: {
+      plugins: [
+        {
+          // Hide the default footer
+          op: PLUGIN_OPERATIONS.Hide,
+          widgetId: 'default_contents',
+        },
+        {
+          // Insert a custom footer
+          op: PLUGIN_OPERATIONS.Insert,
+          widget: {
+            id: 'custom_footer',
+            type: DIRECT_PLUGIN,
+            RenderWidget: () => (
+              <h1 style={{textAlign: 'center'}}>🦶</h1>
+            ),
+          },
+        },
+      ]
+    }
+  },
+}
+
+export default config;
+```