docs: add StefH as a contributor for doc (#1308)

* 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

@@ -354,6 +354,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "StefH",
+      "name": "Stef Heyenrath",
+      "avatar_url": "https://avatars.githubusercontent.com/u/249938?v=4",
+      "profile": "https://sourcerer.io/stefh",
+      "contributions": [
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -75,6 +75,7 @@ Check [all 59 challenges](https://angular-challenges.vercel.app/)
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/michalgrzegorczyk-dev"><img src="https://avatars.githubusercontent.com/u/47832176?v=4?s=100" width="100px;" alt="Michał Grzegorczyk"/><br /><sub><b>Michał Grzegorczyk</b></sub></a><br /><a href="https://github.com/tomalaforge/angular-challenges/commits?author=michalgrzegorczyk-dev" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/tamim36"><img src="https://avatars.githubusercontent.com/u/42251521?v=4?s=100" width="100px;" alt="Tamim Arefin Anik"/><br /><sub><b>Tamim Arefin Anik</b></sub></a><br /><a href="https://github.com/tomalaforge/angular-challenges/issues?q=author%3Atamim36" title="Bug reports">🐛</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/WhoisBsa"><img src="https://avatars.githubusercontent.com/u/36895235?v=4?s=100" width="100px;" alt="Matheus B."/><br /><sub><b>Matheus B.</b></sub></a><br /><a href="https://github.com/tomalaforge/angular-challenges/issues?q=author%3AWhoisBsa" title="Bug reports">🐛</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://sourcerer.io/stefh"><img src="https://avatars.githubusercontent.com/u/249938?v=4?s=100" width="100px;" alt="Stef Heyenrath"/><br /><sub><b>Stef Heyenrath</b></sub></a><br /><a href="https://github.com/tomalaforge/angular-challenges/commits?author=StefH" title="Documentation">📖</a></td>
     </tr>
   </tbody>
   <tfoot>