message: improvement: make playground's middleware settings optional
  use a `Partial` for `settings` key
diff: @@ -8,7 +8,7 @@ export interface MiddlewareOptions {
  workspaceName?: string
  env?: any
  config?: any
  - settings?: ISettings
  + settings?: Partial<ISettings>
  schema?: IntrospectionResult
  tabs?: Tab[]
  codeTheme?: EditorColours
  