feat(docs): add DataStore migration guide with Apollo Client patterns

- Add comprehensive migration guide index page for DataStore to Apollo Client
- Add choose-strategy guide for migration approach selection
- Add set-up-apollo guide for Apollo Client configuration
- Add migrate-crud-operations guide for query and mutation patterns
- Add migrate-relationships guide for handling data relationships
- Add add-local-caching guide for persistent cache and optimistic updates
- Add build-offline-support guide for offline-first functionality
- Add advanced-patterns guide for complex migration scenarios
- Update directory structure to include new migrate-from-datastore section with nested pages
- Provides step-by-step guidance for developers transitioning from DataStore to Apollo Client

Author: Ahmed Hamouda

src/directory/directory.mjs

@@ -1861,6 +1861,32 @@ export const directory = {
                         },
                         {
                           path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/app-uninstall/index.mdx'
+                        },
+                        {
+                          path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/index.mdx',
+                          children: [
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/choose-strategy/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/set-up-apollo/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/migrate-crud-operations/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/migrate-relationships/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/add-local-caching/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/build-offline-support/index.mdx'
+                            },
+                            {
+                              path: 'src/pages/gen1/[platform]/build-a-backend/more-features/datastore/migrate-from-datastore/advanced-patterns/index.mdx'
+                            }
+                          ]
                         }
                       ]
                     },