Add github domain verification

wasn't totally sure from the docs if it should be subdomain.is-a.dev or
my actual subdomain so I looked about the repo and this is what I saw
others had done. If there is an issue LMK

domains/_github-pages-challenge-CiaranMcAleer.ciaranmcaleer.json

@@ -0,0 +1,9 @@
+{
+    "owner": {
+        "username": "ciaranmcaleer",
+        "email": "ciaranjmca@outlook.com"
+    },
+    "records": {
+        "TXT": "43a8bc4d932661f0a308b28d8cd553"
+    }
+}