Add Spectre Components

Add "Components" from Spectre, stories and tests for them:

* ~~Accordions~~
* Autocomplete
* ~~Avatars~~
* Badges
* Bars
* Breadcrumbs
* ~~Cards~~
* ~~Chips~~
* Empty states
* Menus
* ~~Modals~~
* ~~Navs~~
* Pagination
* Panels
* ~~Popovers~~
* Steps
* Tabs
* ~~Tiles~~
* Toasts
* Tooltips

1. Create an issue "Add component {ComponentName}" and state that you're working on it.

2. Follow the same code style as other components:
* Use Standard JS style
* Use component layout described in the readme and as seen in other component files

3. Make a pull request following the [PR template](https://github.com/CodeDraken/spectre-react/blob/master/PULL_REQUEST_TEMPLATE.md) and add a reference to the issue.

https://picturepan2.github.io/spectre/components.html

Comienza leyendo el README del repositorio e inspeccionando los archivos de componentes existentes para entender el layout y el estilo de Standard JS. Elige un componente de Spectre que aún no esté completado, crea su issue separado según lo solicitado y, después, añade el componente, las stories y los tests; utiliza la plantilla de PR al enviar el pull request.

Escrito por el modelo de indexación a partir del texto del issue.