docs: add Kohei-Wada as a contributor for code (#728)

* docs: update README.md [skip ci]

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

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.all-contributorsrc

@@ -319,6 +319,13 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/3052212?v=4",
       "profile": "https://github.com/tku137",
       "contributions": ["code", "doc"]
+    },
+    {
+      "login": "Kohei-Wada",
+      "name": "Kohei Wada",
+      "avatar_url": "https://avatars.githubusercontent.com/u/64008205?v=4",
+      "profile": "https://qiita.com/program3152019",
+      "contributions": ["code"]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -812,6 +812,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/abdennourzahaf"><img src="https://avatars.githubusercontent.com/u/62243290?v=4?s=100" width="100px;" alt="abdennourzahaf"/><br /><sub><b>abdennourzahaf</b></sub></a><br /><a href="https://github.com/CopilotC-Nvim/CopilotChat.nvim/commits?author=abdennourzahaf" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/josiahdenton"><img src="https://avatars.githubusercontent.com/u/44758384?v=4?s=100" width="100px;" alt="Josiah"/><br /><sub><b>Josiah</b></sub></a><br /><a href="https://github.com/CopilotC-Nvim/CopilotChat.nvim/commits?author=josiahdenton" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/tku137"><img src="https://avatars.githubusercontent.com/u/3052212?v=4?s=100" width="100px;" alt="Tony Fischer"/><br /><sub><b>Tony Fischer</b></sub></a><br /><a href="https://github.com/CopilotC-Nvim/CopilotChat.nvim/commits?author=tku137" title="Code">💻</a> <a href="https://github.com/CopilotC-Nvim/CopilotChat.nvim/commits?author=tku137" title="Documentation">📖</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://qiita.com/program3152019"><img src="https://avatars.githubusercontent.com/u/64008205?v=4?s=100" width="100px;" alt="Kohei Wada"/><br /><sub><b>Kohei Wada</b></sub></a><br /><a href="https://github.com/CopilotC-Nvim/CopilotChat.nvim/commits?author=Kohei-Wada" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>