Add documentation to xi-core's rpc.rs
Add documentation to xi-core's rpc.rs

fuchsia-mirror/third_party-xi-editor,google/xi-editor,google/xi-editor,google/xi-editor,fuchsia-mirror/third_party-xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,fuchsia-mirror/third_party-xi-editor