docs: add balavishnuvj as a contributor (#786)

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

Author: allcontributors[bot]

.all-contributorsrc

@@ -1253,6 +1253,15 @@
         "code",
         "test"
       ]
+    },
+    {
+      "login": "balavishnuvj",
+      "name": "balavishnuvj",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/13718688?v=4",
+      "profile": "https://github.com/balavishnuvj",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "repoHost": "https://github.com"

README.md

@@ -296,6 +296,7 @@ Thanks goes to these people ([emoji key][emojis]):
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/Tismas"><img src="https://avatars2.githubusercontent.com/u/13601275?v=4" width="100px;" alt=""/><br /><sub><b>Adam</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=Tismas" title="Code">💻</a> <a href="https://github.com/testing-library/dom-testing-library/commits?author=Tismas" title="Tests">⚠️</a></td>
+    <td align="center"><a href="https://github.com/balavishnuvj"><img src="https://avatars3.githubusercontent.com/u/13718688?v=4" width="100px;" alt=""/><br /><sub><b>balavishnuvj</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=balavishnuvj" title="Code">💻</a></td>
   </tr>
 </table>