readme: fix permissions note in config chapter

README.md

@@ -96,7 +96,7 @@ Configuration will be saved in `~/.config/synadm.yaml`
 
 *Note: To find out your admin user's token in Element-Web: Login as this user - "Click User Avatar" - "All Settings" - "Help & About" - Scroll down - "Advanced" - "Access Token"*
 
-*Note: Be aware that once you configured `synadm`, your admin user's token is saved in the configuration file. If you want to protect it, it is your responsibilty to change file permissions accordingly. When `synadm` first creates this file, it uses whatever default [umask](https://en.wikipedia.org/wiki/Umask) your system provides.*
+*Note: Be aware that once you configured `synadm`, your admin user's token is saved in the configuration file. On Posix compatible systems permissions are set to mode 0600, on other OS's it is your responsibilty to change permissions accordingly.*
 
 ## Usage