docs: add KubaJastrz as a contributor (testing-library#308)

* docs: update README.md * docs: update .all-contributorsrc Co-authored-by: null <46447321+allcontributors[bot]@users.noreply.github.com>

Author: allcontributors[bot]

.all-contributorsrc

@@ -395,6 +395,15 @@
  "contributions": [
  "doc"
  ]
+ },
+ {
+ "login": "KubaJastrz",
+ "name": "Jakub Jastrzębski",
+ "avatar_url": "https://avatars0.githubusercontent.com/u/6443113?v=4",
+ "profile": "https://kubajastrz.com",
+ "contributions": [
+ "doc"
+ ]
  }
  ],
  "contributorsPerLine": 7,

README.md

@@ -89,6 +89,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
  </tr>
  <tr>
  <td align="center"><a href="http://blog.staz.be"><img src="https://avatars0.githubusercontent.com/u/82500?v=4" width="100px;" alt="Olivier Le Thanh Duong"/><br /><sub><b>Olivier Le Thanh Duong</b></sub></a><br /><a href="https://github.com/testing-library/testing-library-docs/commits?author=olethanh" title="Documentation">📖</a></td>
+ <td align="center"><a href="https://kubajastrz.com"><img src="https://avatars0.githubusercontent.com/u/6443113?v=4" width="100px;" alt="Jakub Jastrzębski"/><br /><sub><b>Jakub Jastrzębski</b></sub></a><br /><a href="https://github.com/testing-library/testing-library-docs/commits?author=KubaJastrz" title="Documentation">📖</a></td>
  </tr>
 </table>