docs: add pkarw as a contributor for code (#54)

Adds @pkarw as a contributor for code.

This was requested by grabbou [in this
comment](#53 (comment))

---------

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
Co-authored-by: Mike <[email protected]>

Author: allcontributors[bot]

.all-contributorsrc

@@ -16,6 +16,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "pkarw",
+      "name": "Piotr Karwatka",
+      "avatar_url": "https://avatars.githubusercontent.com/u/211899?v=4",
+      "profile": "http://catchthetornado.com",
+      "contributions": [
+        "code"
+      ]
     }
   ]
 }

README.md

@@ -212,6 +212,7 @@ This functional approach makes the framework particularly well-suited for buildi
   <tbody>
     <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/grabbou"><img src="https://avatars.githubusercontent.com/u/2464966?v=4?s=100" width="100px;" alt="Mike"/><br /><sub><b>Mike</b></sub></a><br /><a href="#code-grabbou" title="Code">💻</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="http://catchthetornado.com"><img src="https://avatars.githubusercontent.com/u/211899?v=4?s=100" width="100px;" alt="Piotr Karwatka"/><br /><sub><b>Piotr Karwatka</b></sub></a><br /><a href="#code-pkarw" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>