feat(editor) shape gfx extension (#11928)

Closes: BS-3211

blocksuite/affine/gfx/shape/src/store.ts

@@ -0,0 +1,19 @@
+import {
+  type StoreExtensionContext,
+  StoreExtensionProvider,
+} from '@blocksuite/affine-ext-loader';
+
+import {
+  shapeToMarkdownAdapterMatcher,
+  shapeToPlainTextAdapterMatcher,
+} from './adapter';
+
+export class ShapeStoreExtension extends StoreExtensionProvider {
+  override name = 'affine-shape-gfx';
+
+  override setup(context: StoreExtensionContext) {
+    super.setup(context);
+    context.register(shapeToMarkdownAdapterMatcher);
+    context.register(shapeToPlainTextAdapterMatcher);
+  }
+}