### Summary
There is a helper that exists in `react-testing-library` to query inputs by their `placeholder`. This PR adds that support.
You **could** achieve this by querying for a `placeholder` prop, or querying for react native `TextInput`s manually and then checking their props, but it felt cleaner to have this contained in the testing library itself. It will also allow you to bypass any other instances that may have a `placeholder` prop that aren't `TextInput`s.
If we don't want to expand the surface of the library further, I completely understand that and am fine with this being closed. Just seems like it may be useful and save some time for several scenarios =)
### Test plan
+ Render a `TextInput` with a `placeholder` prop
+ Query the test instance via `getByPlaceholder` for the input
+ Verify the test instance is found
<!-- Please provide enough information so that others can review your pull request. -->
<!-- Keep pull requests small and focused on a single change. -->
### Summary
Whoopsie
### Test plan
<!-- List the steps with which we can test this change. Provide screenshots if this changes anything visual. -->
* Run docusaurus init
* Add api.md and remove initial files
* Run docusaurus init
* Add api.md and remove initial files
* Add callstack info and remove extra scripts
* Commeent out extra features on home page and Add link to example
* Re Arrange Docs Folder
* add some adjustments
* fix lint
* fix lint
<!-- Please provide enough information so that others can review your pull request. -->
<!-- Keep pull requests small and focused on a single change. -->
### Summary
Existential type (`*`) is long deprecated, let's just use `any` for now.
### Test plan
Added some more Flow typings to `shallow.test.js` that were failing because of existential type.
Kacper Wiszczuk
