message: Add instructions for canPickMany
diff: @@ -33,6 +33,10 @@ export class AzureUserInput implements types.IAzureUserInput, types.AzureUserInp
  persistenceKey = `showQuickPick.${randomUtils.getPseudononymousStringHash(unhashedKey)}`;
  }
  + if (options.canPickMany && options.placeHolder) {
  + options.placeHolder += localize('canPickManyInstructions', " (Press 'Space' to select and 'Enter' to confirm)");
  + }
  +
  const result: T | T[] | undefined = await this.rootUserInput.showQuickPick(this.getOrderedItems(items, persistenceKey, options.suppressPersistence), options);
  if (result === undefined) {
  throw new UserCancelledError();
  