docs: add tkhadir as a contributor (iluwatar#1623)

* docs: update README.md [skip ci]

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

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

Author: allcontributors[bot]

.all-contributorsrc

@@ -1350,6 +1350,15 @@
       "contributions": [
         "translation"
       ]
+    },
+    {
+      "login": "tkhadir",
+      "name": "KHADIR Tayeb",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/45130488?v=4",
+      "profile": "http://libkhadir.fr",
+      "contributions": [
+        "translation"
+      ]
     }
   ],
   "contributorsPerLine": 4,