docs/api/createSelector.md: link to hooks guide (#202)
docs/api/createSelector.md: link to hooks guide (#202)

* docs/api/createSelector.md: link to hooks guide

When I first came to use createSelector it wasn't obvious to me how to use
it with hooks.
The reselect docs don't cover it, and I went down a few rabbit holes
before discovering that the react-redux Hooks docs cover it well.

* Update createSelector.md

reduxjs/redux-toolkit,reduxjs/redux-toolkit