treewide: fix typos and other minor issues

default.nix

@@ -336,7 +336,7 @@ in
         default = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
         defaultText = literalMD "see [source](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/default.nix)";
         description = ''
-          Certifificate trust anchors used to verify the LDAP server certificate.
+          Certificate trust anchors used to verify the LDAP server certificate.
         '';
       };
 
@@ -948,10 +948,11 @@ in
       ];
       default = "rsa";
       description = ''
-        The key type used for generating DKIM keys. ED25519 was introduced in RFC6376 (2018).
+        The key type used for generating DKIM keys. Ed25519 support was
+        introduced in RFC6376 (2018).
 
         :::{warning}
-        ED25519 DKIM keys are currently not recommended for primary use, as
+        Ed25519 DKIM keys are currently not recommended for primary use, as
         various DKIM validators out there lack support and consider the keypair invalid.
         :::