Fix various issues in the storage option descriptiosn

Especially a mistake where I confused rst and markdown syntax for
referencing options.

default.nix

@@ -805,8 +805,7 @@ in
           - /var/vmail/example.com/user/.folder.subfolder/ (Maildir++ layout)
           - /var/vmail/example.com/user/folder/subfolder/  (FS layout)
 
-          See <https://doc.dovecot.org/main/core/config/mailbox_formats/maildir.html#directory-layout>
+          See <https://doc.dovecot.org/main/core/config/mailbox_formats/maildir.html#directory-layout> for further details.
-          See https://doc.dovecot.org/main/core/config/mailbox_formats/maildir.html#maildir-mailbox-format for details.
         '';
       };
 
@@ -821,7 +820,7 @@ in
 
           :::{warning}
           If you change this value you also need to manually adjust the
-          permissions of your :option:`mailserver.storage.path`.
+          ownership of your {option}`mailserver.storage.path`.
           :::
         '';
       };
@@ -830,7 +829,7 @@ in
         type = types.str;
         default = "virtualMail";
         description = ''
-          The name of the user that owns the :option:`mailserver.storage.path`.
+          The name of the user that owns the {option}`mailserver.storage.path`.
         '';
       };
 
@@ -845,7 +844,7 @@ in
 
           :::{warning}
           If you change this value you also need to manually adjust the
-          permissions of your :option:`mailserver.storage.path`.
+          ownership of your {option}`mailserver.storage.path`.
           :::
         '';
       };
@@ -855,7 +854,7 @@ in
         default = "virtualMail";
         description = ''
           The primary group name of the user that owns the
-          :option:`mailserver.storage.path`.
+          {option}`mailserver.storage.path`.
         '';
       };
     };