message: docs: add comments to vscode-context
diff: import * as vscode from 'vscode';
  -export class VsCodeContextImpl {
  +/**
  + * Wrapper around VS Code's `setContext`.
  + * The API call takes several milliseconds to seconds to complete,
  + * so let's cache the values and only call the API when necessary.
  + */
  +class VsCodeContextImpl {
  contextMap: { [key: string]: any } = {};
  public async Set(key: string, value: any): Promise<void> {
  