docs: update @Offirmo as a contributor

.all-contributorsrc

@@ -69,7 +69,8 @@
  "avatar_url": "https://avatars0.githubusercontent.com/u/603503?v=4",
  "profile": "http:https://www.offirmo.net/",
  "contributions": [
- "ideas"
+ "ideas",
+ "code"
  ]
  }
  ],

README.md

@@ -122,7 +122,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
  <td align="center"><a href="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/qpowell"><img src="https://avatars2.githubusercontent.com/u/1351050?v=4" width="100px;" alt="Quinten Powell"/><br /><sub><b>Quinten Powell</b></sub></a><br /><a href="https://github.com/mike-engel/a11y-css-reset/commits?author=qpowell" title="Documentation">📖</a></td>
  <td align="center"><a href="https://gitlab.com/toastal"><img src="https://avatars2.githubusercontent.com/u/561087?v=4" width="100px;" alt="toastal"/><br /><sub><b>toastal</b></sub></a><br /><a href="https://github.com/mike-engel/a11y-css-reset/commits?author=toastal" title="Code">💻</a></td>
  <td align="center"><a href="http:https://notiv.org/"><img src="https://avatars0.githubusercontent.com/u/10743009?v=4" width="100px;" alt="Mikhail Novikov"/><br /><sub><b>Mikhail Novikov</b></sub></a><br /><a href="https://github.com/mike-engel/a11y-css-reset/commits?author=notiv-nt" title="Code">💻</a></td>
- <td align="center"><a href="http:https://www.offirmo.net/"><img src="https://avatars0.githubusercontent.com/u/603503?v=4" width="100px;" alt="offirmo"/><br /><sub><b>offirmo</b></sub></a><br /><a href="#ideas-Offirmo" title="Ideas, Planning, & Feedback">🤔</a></td>
+ <td align="center"><a href="http:https://www.offirmo.net/"><img src="https://avatars0.githubusercontent.com/u/603503?v=4" width="100px;" alt="offirmo"/><br /><sub><b>offirmo</b></sub></a><br /><a href="#ideas-Offirmo" title="Ideas, Planning, & Feedback">🤔</a> <a href="https://github.com/mike-engel/a11y-css-reset/commits?author=Offirmo" title="Code">💻</a></td>
  </tr>
 </table>