Add www subdomain, redirecting to jithesh-gopinathan.is-a.dev

- domains/www.jithesh-gopinathan.json: CNAME for the www subdomain,
  set up in Vercel as a 308 redirect to the bare domain (which stays
  canonical -- it's the one actually registered as the root entry).
- domains/_vercel.www.jithesh-gopinathan.json: TXT ownership
  verification Vercel requires before it will accept the redirect,
  same pattern as the existing _vercel.jithesh-gopinathan.json record.

domains/_vercel.www.jithesh-gopinathan.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+    "username": "jitheshlive",
+    "email": "jitheshlive@gmail.com"
+  },
+  "records": {
+    "TXT": "vc-domain-verify=www.jithesh-gopinathan.is-a.dev,3a62b2f626fc5d0d997b"
+  }
+}

domains/www.jithesh-gopinathan.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+    "username": "jitheshlive",
+    "email": "jitheshlive@gmail.com"
+  },
+  "records": {
+    "CNAME": "548567b959fb146d.vercel-dns-017.com"
+  }
+}