Add ProtonMail domain key configuration

domains/protonmail3._domainkey.javier.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+   "username": "Javiito32",
+     "email": "hola@javiito.com"
+  },
+ "records": {
+   "TXT": "protonmail3.domainkey.ds7be42nlejh7nlp7bvy33bhpppemtjhm4lb2sbtab37qahx7tbhq.domains.proton.ch."
+  }
+}