docs: add mikestecker as a contributor for code, test, doc (#27)

* docs: update README.md

* docs: update .all-contributorsrc

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

.all-contributorsrc

@@ -72,6 +72,17 @@
         "code",
         "bug"
       ]
+    },
+    {
+      "login": "mikestecker",
+      "name": "Mike Stecker",
+      "avatar_url": "https://avatars.githubusercontent.com/u/407465?v=4",
+      "profile": "https://github.com/mikestecker",
+      "contributions": [
+        "code",
+        "test",
+        "doc"
+      ]
     }
   ]
 }

README.md

@@ -456,6 +456,7 @@ Thanks goes to these people ([emoji key][emojis]):
     <td align="center"><a href="https://www.osiux.ws/"><img src="https://avatars2.githubusercontent.com/u/204463?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Eduardo Reveles</b></sub></a><br /><a href="https://github.com/remark-embedder/core/commits?author=osiux" title="Code">💻</a></td>
     <td align="center"><a href="http://wooorm.com"><img src="https://avatars0.githubusercontent.com/u/944406?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Titus</b></sub></a><br /><a href="https://github.com/remark-embedder/core/pulls?q=is%3Apr+reviewed-by%3Awooorm" title="Reviewed Pull Requests">👀</a></td>
     <td align="center"><a href="https://bradgarropy.com"><img src="https://avatars2.githubusercontent.com/u/11336745?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Brad Garropy</b></sub></a><br /><a href="https://github.com/remark-embedder/core/commits?author=bradgarropy" title="Code">💻</a> <a href="https://github.com/remark-embedder/core/issues?q=author%3Abradgarropy" title="Bug reports">🐛</a></td>
+    <td align="center"><a href="https://github.com/mikestecker"><img src="https://avatars.githubusercontent.com/u/407465?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Mike Stecker</b></sub></a><br /><a href="https://github.com/remark-embedder/core/commits?author=mikestecker" title="Code">💻</a> <a href="https://github.com/remark-embedder/core/commits?author=mikestecker" title="Tests">⚠️</a> <a href="https://github.com/remark-embedder/core/commits?author=mikestecker" title="Documentation">📖</a></td>
   </tr>
 </table>