Update caue.is-a.dev: site + ImprovMX email

Point CNAME to alientech.app.br and add ImprovMX MX/SPF with proxied enabled so the website and mail forwarding can coexist.

domains/caue.json

@@ -4,6 +4,14 @@
     "email": "cauepinhal@gmail.com"
   },
   "records": {
-    "CNAME": "dev.caue.xyz"
-  }
+    "CNAME": "alientech.app.br",
+    "MX": [
+      "mx1.improvmx.com",
+      "mx2.improvmx.com"
+    ],
+    "TXT": [
+      "v=spf1 include:spf.improvmx.com ~all"
+    ]
+  },
+  "proxied": true
 }