docs: add bookun as a contributor (#357)

.all-contributorsrc

@@ -288,6 +288,15 @@
         "doc",
         "translation"
       ]
+    },
+    {
+      "login": "bookun",
+      "name": "Kutsuzawa Ryo",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/10346162?v=4",
+      "profile": "https://twitter.com/bookun2851",
+      "contributions": [
+        "review"
+      ]
     }
   ],
   "contributorsPerLine": 7

README.md

@@ -219,6 +219,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/Hofer-Julian"><img src="https://avatars1.githubusercontent.com/u/30049909?v=4" width="100px;" alt="Hofer-Julian"/><br /><sub><b>Hofer-Julian</b></sub></a><br /><a href="https://github.com/starship/starship/commits?author=Hofer-Julian" title="Documentation">📖</a></td>
     <td align="center"><a href="http://blog.unhappychoice.com"><img src="https://avatars3.githubusercontent.com/u/5608948?v=4" width="100px;" alt="Yuji Ueki"/><br /><sub><b>Yuji Ueki</b></sub></a><br /><a href="#content-unhappychoice" title="Content">🖋</a> <a href="#translation-unhappychoice" title="Translation">🌍</a></td>
     <td align="center"><a href="https://github.com/heyrict"><img src="https://avatars3.githubusercontent.com/u/25698503?v=4" width="100px;" alt="谢祯晖"/><br /><sub><b>谢祯晖</b></sub></a><br /><a href="https://github.com/starship/starship/commits?author=heyrict" title="Code">💻</a> <a href="https://github.com/starship/starship/commits?author=heyrict" title="Documentation">📖</a> <a href="#translation-heyrict" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://twitter.com/bookun2851"><img src="https://avatars2.githubusercontent.com/u/10346162?v=4" width="100px;" alt="Kutsuzawa Ryo"/><br /><sub><b>Kutsuzawa Ryo</b></sub></a><br /><a href="#review-bookun" title="Reviewed Pull Requests">👀</a></td>
   </tr>
 </table>