docs: add JoshuaKGoldberg as a contributor (#647)

* docs: update README.md

* docs: update .all-contributorsrc

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

Author: allcontributors[bot]

.all-contributorsrc

@@ -1065,6 +1065,16 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "JoshuaKGoldberg",
+      "name": "Josh Goldberg",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/3335181?v=4",
+      "profile": "http://www.joshuakgoldberg.com",
+      "contributions": [
+        "code",
+        "test"
+      ]
     }
   ],
   "repoHost": "https://github.com"

README.md

@@ -270,6 +270,7 @@ Thanks goes to these people ([emoji key][emojis]):
     <td align="center"><a href="https://github.com/tjefferson08"><img src="https://avatars2.githubusercontent.com/u/3535390?v=4" width="100px;" alt=""/><br /><sub><b>Travis Jefferson</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=tjefferson08" title="Code">💻</a> <a href="https://github.com/testing-library/dom-testing-library/commits?author=tjefferson08" title="Tests">⚠️</a></td>
     <td align="center"><a href="https://github.com/mdjastrzebski"><img src="https://avatars2.githubusercontent.com/u/6368606?v=4" width="100px;" alt=""/><br /><sub><b>Maciej Jastrzebski</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/issues?q=author%3Amdjastrzebski" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://commonlit.org"><img src="https://avatars3.githubusercontent.com/u/319471?v=4" width="100px;" alt=""/><br /><sub><b>Geoff Harcourt</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=geoffharcourt" title="Code">💻</a></td>
+    <td align="center"><a href="http://www.joshuakgoldberg.com"><img src="https://avatars1.githubusercontent.com/u/3335181?v=4" width="100px;" alt=""/><br /><sub><b>Josh Goldberg</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=JoshuaKGoldberg" title="Code">💻</a> <a href="https://github.com/testing-library/dom-testing-library/commits?author=JoshuaKGoldberg" title="Tests">⚠️</a></td>
   </tr>
 </table>