docs: add mbeale as a contributor for doc (#1293)

* docs: update CONTRIBUTING.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

---------

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

.all-contributorsrc

@@ -389,6 +389,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "mbeale",
+      "name": "Michael Beale",
+      "avatar_url": "https://avatars.githubusercontent.com/u/1507647?v=4",
+      "profile": "http://themichaelbeale.com",
+      "contributions": [
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 7,

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-42-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-43-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 ## Contributors ✨
@@ -66,6 +66,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/GregVS"><img src="https://avatars.githubusercontent.com/u/83143490?v=4?s=100" width="100px;" alt="Gregory Saldanha"/><br /><sub><b>Gregory Saldanha</b></sub></a><br /><a href="https://github.com/py-why/dowhy/commits?author=GregVS" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/vivianqin214"><img src="https://avatars.githubusercontent.com/u/56522949?v=4?s=100" width="100px;" alt="vivianqin214"/><br /><sub><b>vivianqin214</b></sub></a><br /><a href="https://github.com/py-why/dowhy/commits?author=vivianqin214" title="Code">💻</a></td>
     </tr>
+    <tr>
+      <td align="center" valign="top" width="14.28%"><a href="http://themichaelbeale.com"><img src="https://avatars.githubusercontent.com/u/1507647?v=4?s=100" width="100px;" alt="Michael Beale"/><br /><sub><b>Michael Beale</b></sub></a><br /><a href="https://github.com/py-why/dowhy/commits?author=mbeale" title="Documentation">📖</a></td>
+    </tr>
   </tbody>
 </table>