Update README.md

Author: BohuTANG

src/meta/README.md

@@ -4,7 +4,6 @@ Databend Meta is a transactional metadata service.
 
 - [`api`](./api/), the user level api interface exposed based on the KVApi implementation.
 - [`app`](./app/), defines meta data types used by meta-client application.
-- [`embedded`](./embedded/), a meta store backed with a local sled::Tree.
 - [`grpc`](client/), the client library based on grpc and is used to communicate with meta service.
 - [`protos`](./protos/) defines the protobuf messages a meta client talks to a meta server.
 - [`proto-conv`](./proto-conv/) defines how to convert metadata types in rust from and to protobuf messages.