docs: add amangoel185 as a contributor for code (#639)

* 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

@@ -165,7 +165,8 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/10528392?v=4",
       "profile": "http://amangoel.me",
       "contributions": [
-        "doc"
+        "doc",
+        "code"
       ]
     }
   ],

README.md

@@ -255,7 +255,7 @@ We would like to acknowledge the contributors that made this project possible ([
   <tr>
     <td align="center"><a href="https://keybase.io/kgizdov"><img src="https://avatars.githubusercontent.com/u/3164953?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Konstantin Gizdov</b></sub></a><br /><a href="#platform-kgizdov" title="Packaging/porting to new platform">📦</a> <a href="https://github.com/scikit-hep/boost-histogram/issues?q=author%3Akgizdov" title="Bug reports">🐛</a></td>
     <td align="center"><a href="http://theoryandpractice.org"><img src="https://avatars.githubusercontent.com/u/4458890?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Kyle Cranmer</b></sub></a><br /><a href="https://github.com/scikit-hep/boost-histogram/commits?author=cranmer" title="Documentation">📖</a></td>
-    <td align="center"><a href="http://amangoel.me"><img src="https://avatars.githubusercontent.com/u/10528392?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Aman Goel</b></sub></a><br /><a href="https://github.com/scikit-hep/boost-histogram/commits?author=amangoel185" title="Documentation">📖</a></td>
+    <td align="center"><a href="http://amangoel.me"><img src="https://avatars.githubusercontent.com/u/10528392?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Aman Goel</b></sub></a><br /><a href="https://github.com/scikit-hep/boost-histogram/commits?author=amangoel185" title="Documentation">📖</a> <a href="https://github.com/scikit-hep/boost-histogram/commits?author=amangoel185" title="Code">💻</a></td>
   </tr>
 </table>