docs: add danwilhelm as a contributor (#323)

* docs: update README.md [skip ci]

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

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

.all-contributorsrc

@@ -188,6 +188,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "danwilhelm",
+      "name": "Dan Wilhelm",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/6137185?v=4",
+      "profile": "http://danwilhelm.com",
+      "contributions": [
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 10,

README.md

@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-20-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-21-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️ [![Build status](https://badge.buildkite.com/7af93d81dc522c67a1ec8e33ff5705861b1cb36360b774807f.svg)](https://buildkite.com/mokou/rustlings)
@@ -162,6 +162,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="http://about.me/BrianKung"><img src="https://avatars1.githubusercontent.com/u/2836167?v=4" width="100px;" alt=""/><br /><sub><b>Brian Kung</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=briankung" title="Code">💻</a> <a href="#content-briankung" title="Content">🖋</a></td>
     <td align="center"><a href="https://rcousineau.gitlab.io"><img src="https://avatars3.githubusercontent.com/u/281039?v=4" width="100px;" alt=""/><br /><sub><b>Russell</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=miller-time" title="Code">💻</a></td>
   </tr>
+  <tr>
+    <td align="center"><a href="http://danwilhelm.com"><img src="https://avatars3.githubusercontent.com/u/6137185?v=4" width="100px;" alt=""/><br /><sub><b>Dan Wilhelm</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=danwilhelm" title="Documentation">📖</a></td>
+  </tr>
 </table>
 
 <!-- markdownlint-enable -->