Add domainsearch index file

Fixes #4

Add a new `domainsearch/index.ts` file to the repository.

* **Imports:**
  - Import `DomainSearch` from `components/DomainSearch/DomainSearch`
  - Import `FavoritesList` from `components/DomainSearch/FavoritesList`
  - Import `SearchForm` from `components/DomainSearch/SearchForm`
  - Import `SearchResults` from `components/DomainSearch/SearchResults`
* **Exports:**
  - Export `DomainSearch`, `FavoritesList`, `SearchForm`, and `SearchResults`
* Add `.devcontainer.json` file with build task configuration.
* Add `package-lock.json` file with basic package information.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/ggindev/domain-pro-check/issues/4?shareId=XXXX-XXXX-XXXX-XXXX).

.devcontainer.json

@@ -0,0 +1,5 @@
+{
+  "tasks": {
+    "build": "npm run dev"
+  }
+}

domainsearch/index.ts

@@ -0,0 +1,6 @@
+import DomainSearch from '../components/DomainSearch/DomainSearch';
+import FavoritesList from '../components/DomainSearch/FavoritesList';
+import SearchForm from '../components/DomainSearch/SearchForm';
+import SearchResults from '../components/DomainSearch/SearchResults';
+
+export { DomainSearch, FavoritesList, SearchForm, SearchResults };