feat(Stepper): new component (#2733)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/theme/index.ts

@@ -37,6 +37,7 @@ export { default as separator } from './separator'
 export { default as skeleton } from './skeleton'
 export { default as slideover } from './slideover'
 export { default as slider } from './slider'
+export { default as stepper } from './stepper'
 export { default as switch } from './switch'
 export { default as table } from './table'
 export { default as tabs } from './tabs'