Address review comments

editors/code/src/config.ts

@@ -287,6 +287,14 @@ export class Config {
     }
 }
 
+// the optional `cb?` parameter is meant to be used to add additional
+// key/value pairs to the VS Code configuration. This needed for, e.g.,
+// including a `rust-project.json` into the `linkedProjects` key as part
+// of the configuration/InitializationParams _without_ causing VS Code
+// configuration to be written out to workspace-level settings. This is
+// undesirable behavior because rust-project.json files can be tens of
+// thousands of lines of JSON, most of which is not meant for humans
+// to interact with.
 export function prepareVSCodeConfig<T>(
     resp: T,
     cb?: (key: Extract<keyof T, string>, res: { [key: string]: any }) => void