docs: SetupContext.refs type, remove unnecessary docs

[subdavis]

Fix docs bug introduced by #595

Error

ERROR in /home/user/github.com/VIAME-Web/client/platform/web-girder/views/ViewerLoader.vue(16,14):
16:14 Subsequent property declarations must have the same type.  Property 'refs' must be of type 'Data', but here has type '{ [key: string]: Element | Element[] | Vue | Vue[]; }'.
    14 | declare module '@vue/composition-api' {
    15 |   interface SetupContext {
  > 16 |     readonly refs: { [key: string]: Vue | Element | Vue[] | Element[] }
       |              ^
    17 |   }
    18 | }
    19 | /**

Type of refs changed to unexported type Data. I've verified that this change works on a local project.

[pikax]

readonly refs: { [key: string]: Vue | Element | Vue[] | Element[] } is the correct type for refs.

[subdavis]

I agree, that should be the correct type. But it won't build since a conflicting type was added. Your snippet will not build as a result of #595 via "^1.0.0-beta.18"

Either the type needs to change or the docs need to change. It should probably be corrected here instead:

https://github.com/antfu/composition-api/blob/b7e178e23d75f59cf2af7881debe53911cb57979/src/component/componentOptions.ts#L28

I assume the person that wrote that line saw the existing Data and used it, unaware of the existing documentation issue it would cause.

[pikax]

Can you change https://github.com/vuejs/composition-api/blob/master/src/component/componentOptions.ts#L28 instead to have the correct type?

[pikax]

Thank you