Merge pull request #568 from himself65/docs-update

docs: add `@toeverything/y-indexeddb`

README.md

@@ -155,6 +155,11 @@ Encryption (E2EE).
   <dd>
 Adds persistent storage to a server with MongoDB. Can be used with the
 y-websocket provider.
+</dd>
+  <dt><a href="https://github.com/toeverything/AFFiNE/tree/master/packages/y-indexeddb">
+@toeverything/y-indexeddb</a></dt>
+  <dd>
+Like y-indexeddb, but with sub-documents support and fully TypeScript.
 </dd>
 </dl>