title: Use Active Storage without Rails
body: <p>There is a case we want to use the Active Storage without Rails. We are using activemodel, activejob in Gemfile. we would like to use activestorage in our ruby application.</p>
  <p>Is it possible to configure and use activestorage without rails? if so can anyone please give us the suggestion how to configure and use.</p>
  <p>Thanks in advance!</p>