docs: add paularmstrong as a contributor (#275)

* docs: update README.md

* docs: update .all-contributorsrc

Author: allcontributors[bot]

.all-contributorsrc

@@ -583,6 +583,16 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "paularmstrong",
+      "name": "Paul Armstrong",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/33297?v=4",
+      "profile": "https://github.com/paularmstrong",
+      "contributions": [
+        "code",
+        "test"
+      ]
     }
   ],
   "repoHost": "https://github.com"