feat: add stop method

[clemgbld]

Closes #219

the script that i used for visual testing:

import { Spinner } from "./dist/index.js"

const spinner1 = new Spinner();
const spinner2 = new Spinner();
const spinner3 = new Spinner();


spinner1.start("Loading... 1");
spinner2.start("Loading... 2");
spinner3.start("Loading... 3");

spinner1.stop();
spinner2.stop();
spinner3.stop();
for (let i = 0; i <= 10; i++) {
  console.log(`Step ${i}`)
}
spinner1.start();
spinner2.start();
spinner3.start();

setTimeout(() => {
  spinner1.stop();
  spinner2.stop();
  spinner3.stop();
  for (let i = 0; i <= 10; i++) {
    console.log(`Step ${i}`)
  }
  spinner1.start();
  spinner2.start();
  spinner3.start();
  setTimeout(() => {
    spinner1.succeed("end 1");
    spinner2.succeed("end 2");
    spinner3.succeed("end 3");

  }, 2000);

}, 2000);