WIP: Append more languages on implementing of the extra backend

content/advanced/development.md

@@ -25,11 +25,21 @@ In order to create a new backend you need:
 
 - If there are changes required to the protobuf code, modify the [proto](https://github.com/go-skynet/LocalAI/blob/master/pkg/grpc/proto/backend.proto) file and re-generate the code with `make protogen`.
 - Modify the `Makefile` to add your new backend and re-generate the client code with `make protogen` if necessary.
-- Create a new `gRPC` server in `extra/grpc` if it's not written in go: [link](https://github.com/go-skynet/LocalAI/tree/master/extra/grpc), and create the specific implementation.
+- Create a new `gRPC` server in `extra/grpc`
+  - Golang 
     - Golang `gRPC` servers should be added in the [pkg/backend](https://github.com/go-skynet/LocalAI/tree/master/pkg/backend) directory given their type. See [piper](https://github.com/go-skynet/LocalAI/blob/master/pkg/backend/tts/piper.go) as an example.
     - Golang servers needs a respective `cmd/grpc` binary that must be created too, see also [cmd/grpc/piper](https://github.com/go-skynet/LocalAI/tree/master/cmd/grpc/piper) as an example, update also the Makefile accordingly to build the binary during build time.
+  - Python
+    - The `gRPC` server should be added in the [extra/grpc](https://github.com/go-skynet/LocalAI/tree/master/extra/grpc) directory. Here we create a seperate Python environment for every extra `gRPC` server which was implemented in Python. Check the README.md in the directory for more information.
+  - Rust
+    - The `gRPC` server should be added in the [extra/grpc](https://github.com/go-skynet/LocalAI/tree/master/extra/grpc) directory. The Rust backend is still in discussion and not implemented yet. And we will update the README.md in the directory for more information.
+  - C++
+    - The `gRPC` server should be added in the [extra/grpc](https://github.com/go-skynet/LocalAI/tree/master/extra/grpc) directory. The C++ backend is still in discussion and not implemented yet. And we will update the README.md in the directory for more information.
+
 - Update the Dockerfile: if the backend is written in another language, update the `Dockerfile` default *EXTERNAL_GRPC_BACKENDS* variable by listing the new binary [link](https://github.com/go-skynet/LocalAI/blob/c2233648164f67cdb74dd33b8d46244e14436ab3/Dockerfile#L14).
 
+- Update the `Makefile` to build the new backend binary. Will update after the backend is implemented.
+
 Once you are done, you can either re-build `LocalAI` with your backend or you can try it out by running the `gRPC` server manually and specifying the host and IP to LocalAI with `--external-grpc-backends` or using (`EXTERNAL_GRPC_BACKENDS` environment variable, comma separated list of `name:host:port` tuples, e.g. `my-awesome-backend:host:port`):
 
 ```bash