0.1.12: Add slider (#78)

* Add section in docs

* Hide range input on all browsers

Displays indicator as radio outline on Windows 10 Firefox 75

* Add svg icons

* Add thumb styling on range input

* Add track to range input

* Add indicator css for has-recatangular-indicator

* Update styling and labels for range input

* Update example for simple range input

* Remove repeated code

* Remove unused icon and add vertical input style

* Refactor styling and adapt description to fit

* Add style for all vertical lengths and update docs

* Correct 2x to 2px