docs: add peterchen96 as a contributor for code, doc (#459)

* 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]

.all-contributorsrc

@@ -356,6 +356,16 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "peterchen96",
+      "name": "Peter Chen",
+      "avatar_url": "https://avatars.githubusercontent.com/u/25033565?v=4",
+      "profile": "https://github.com/peterchen96",
+      "contributions": [
+        "code",
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -223,6 +223,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/LaarsOman"><img src="https://avatars.githubusercontent.com/u/88617671?v=4?s=100" width="100px;" alt=""/><br /><sub><b>LaarsOman</b></sub></a><br /><a href="https://github.com/JuliaReinforcementLearning/ReinforcementLearning.jl/commits?author=LaarsOman" title="Documentation">📖</a></td>
     <td align="center"><a href="https://github.com/burmecia"><img src="https://avatars.githubusercontent.com/u/19306324?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Bo Lu</b></sub></a><br /><a href="https://github.com/JuliaReinforcementLearning/ReinforcementLearning.jl/commits?author=burmecia" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/peterchen96"><img src="https://avatars.githubusercontent.com/u/25033565?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Peter Chen</b></sub></a><br /><a href="https://github.com/JuliaReinforcementLearning/ReinforcementLearning.jl/commits?author=peterchen96" title="Code">💻</a> <a href="https://github.com/JuliaReinforcementLearning/ReinforcementLearning.jl/commits?author=peterchen96" title="Documentation">📖</a></td>
   </tr>
 </table>