docs: add tibshirani as a contributor for code, and content (#14)

* 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

@@ -26,6 +26,16 @@
         "code",
         "content"
       ]
+    },
+    {
+      "login": "tibshirani",
+      "name": "tibshirani",
+      "avatar_url": "https://avatars.githubusercontent.com/u/2848609?v=4",
+      "profile": "https://github.com/tibshirani",
+      "contributions": [
+        "code",
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -1,6 +1,6 @@
 # ISLP
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-2-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-3-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 This package collects data sets and various helper functions
@@ -86,6 +86,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/danielawitten"><img src="https://avatars.githubusercontent.com/u/12654191?v=4?s=100" width="100px;" alt="danielawitten"/><br /><sub><b>danielawitten</b></sub></a><br /><a href="https://github.com/intro-stat-learning/ISLP/commits?author=danielawitten" title="Code">💻</a> <a href="#content-danielawitten" title="Content">🖋</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://web.stanford.edu/~hastie/"><img src="https://avatars.githubusercontent.com/u/13293253?v=4?s=100" width="100px;" alt="trevorhastie"/><br /><sub><b>trevorhastie</b></sub></a><br /><a href="https://github.com/intro-stat-learning/ISLP/commits?author=trevorhastie" title="Code">💻</a> <a href="#content-trevorhastie" title="Content">🖋</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/tibshirani"><img src="https://avatars.githubusercontent.com/u/2848609?v=4?s=100" width="100px;" alt="tibshirani"/><br /><sub><b>tibshirani</b></sub></a><br /><a href="https://github.com/intro-stat-learning/ISLP/commits?author=tibshirani" title="Code">💻</a> <a href="#content-tibshirani" title="Content">🖋</a></td>
     </tr>
   </tbody>
 </table>