docs: migrate to @nuxthq/ui-kit (#405)

Co-authored-by: Sébastien Chopin <seb@nuxt.com>

docs/content/6.overlays/1.modal.md

@@ -1,9 +1,12 @@
 ---
-github: true
 description: Display a modal within your application.
-headlessui:
-  label: 'Dialog'
-  to: 'https://headlessui.com/vue/dialog'
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/Modal.vue
+  - label: 'Dialog'
+    icon: i-simple-icons-headlessui
+    to: 'https://headlessui.com/vue/dialog'
 ---
 
 ## Usage

docs/content/6.overlays/2.slideover.md

@@ -1,9 +1,12 @@
 ---
-github: true
 description: Display a dialog that slides in from the edge of the screen.
-headlessui:
-  label: 'Dialog'
-  to: 'https://headlessui.com/vue/dialog'
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/Slideover.vue
+  - label: 'Dialog'
+    icon: i-simple-icons-headlessui
+    to: 'https://headlessui.com/vue/dialog'
 ---
 
 ## Usage

docs/content/6.overlays/3.popover.md

@@ -1,9 +1,12 @@
 ---
-github: true
 description: Display a non-modal dialog that floats around a trigger element.
-headlessui:
-  label: 'Popover'
-  to: 'https://headlessui.com/vue/popover'
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/Popover.vue
+  - label: 'Popover'
+    icon: i-simple-icons-headlessui
+    to: 'https://headlessui.com/vue/popover'
 ---
 
 ## Usage

docs/content/6.overlays/4.tooltip.md

@@ -1,6 +1,9 @@
 ---
-github: true
 description: Display content that appears on hover next to an element.
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/Tooltip.vue
 ---
 
 ## Usage

docs/content/6.overlays/5.context-menu.md

@@ -1,6 +1,9 @@
 ---
-github: true
 description: Display a menu that appears on right click.
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/ContextMenu.vue
 ---
 
 ## Usage

docs/content/6.overlays/6.notification.md

@@ -1,6 +1,9 @@
 ---
-github: true
 description: Display a toast notification in your app.
+links:
+  - label: GitHub
+    icon: i-simple-icons-github
+    to: https://github.com/nuxtlabs/ui/blob/dev/src/runtime/components/overlays/Notification.vue
 ---
 
 ## Usage