docs: add G-Rath as a contributor (#383)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>

Author: allcontributors[bot]

.all-contributorsrc

@@ -402,6 +402,17 @@
         "code",
         "test"
       ]
+    },
+    {
+      "login": "G-Rath",
+      "name": "Gareth Jones",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3151613?v=4",
+      "profile": "https://github.com/G-Rath",
+      "contributions": [
+        "code",
+        "doc",
+        "test"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -359,6 +359,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/ph-fritsche"><img src="https://avatars.githubusercontent.com/u/39068198?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Philipp Fritsche</b></sub></a><br /><a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=ph-fritsche" title="Code">💻</a></td>
     <td align="center"><a href="http://zaicevas.me"><img src="https://avatars.githubusercontent.com/u/34719980?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tomas Zaicevas</b></sub></a><br /><a href="https://github.com/testing-library/eslint-plugin-testing-library/issues?q=author%3Azaicevas" title="Bug reports">🐛</a> <a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=zaicevas" title="Code">💻</a> <a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=zaicevas" title="Tests">⚠️</a></td>
+    <td align="center"><a href="https://github.com/G-Rath"><img src="https://avatars.githubusercontent.com/u/3151613?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Gareth Jones</b></sub></a><br /><a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=G-Rath" title="Code">💻</a> <a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=G-Rath" title="Documentation">📖</a> <a href="https://github.com/testing-library/eslint-plugin-testing-library/commits?author=G-Rath" title="Tests">⚠️</a></td>
   </tr>
 </table>