feat(api-docs): create new plugin

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

plugins/api-docs/src/alpha.tsx

@@ -13,3 +13,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+import { createPlugin } from '@backstage/frontend-plugin-api';
+import { convertLegacyRouteRef } from '@backstage/core-compat-api';
+import { rootRoute, registerComponentRouteRef } from './routes';
+
+export default createPlugin({
+  id: 'api-docs',
+  routes: {
+    root: convertLegacyRouteRef(rootRoute),
+  },
+  externalRoutes: {
+    registerApi: convertLegacyRouteRef(registerComponentRouteRef),
+  },
+  extensions: [],
+});