docs: add Joel-Dandin as a contributor for code (iluwatar#3003)

* 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]

Diff for: .all-contributorsrc

@@ -3150,6 +3150,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "Joel-Dandin",
+      "name": "Joel",
+      "avatar_url": "https://avatars.githubusercontent.com/u/60149879?v=4",
+      "profile": "https://github.com/Joel-Dandin",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 6,

Diff for: README.md

@@ -6,7 +6,7 @@
 [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=coverage)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-345-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-346-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 <br/>
@@ -520,6 +520,7 @@ This project is licensed under the terms of the MIT license.
       <td align="center" valign="top" width="16.66%"><a href="https://github.com/Avinash2110"><img src="https://avatars.githubusercontent.com/u/37360069?v=4?s=100" width="100px;" alt="Avinash Shukla"/><br /><sub><b>Avinash Shukla</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Avinash2110" title="Code">💻</a></td>
       <td align="center" valign="top" width="16.66%"><a href="https://github.com/Mayankchoudhary294"><img src="https://avatars.githubusercontent.com/u/97609699?v=4?s=100" width="100px;" alt="Mayank Choudhary"/><br /><sub><b>Mayank Choudhary</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Mayankchoudhary294" title="Code">💻</a></td>
       <td align="center" valign="top" width="16.66%"><a href="https://github.com/romannimets"><img src="https://avatars.githubusercontent.com/u/137268574?v=4?s=100" width="100px;" alt="romannimets"/><br /><sub><b>romannimets</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=romannimets" title="Code">💻</a></td>
+      <td align="center" valign="top" width="16.66%"><a href="https://github.com/Joel-Dandin"><img src="https://avatars.githubusercontent.com/u/60149879?v=4?s=100" width="100px;" alt="Joel"/><br /><sub><b>Joel</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Joel-Dandin" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>