Fixed a small typo

Author: sallesviana

_docs/sysadmin/installation.md

@@ -128,7 +128,7 @@ Note: These instructions should be run under root
    the machine, one way to do this is:
 
    ```
-   ls /home > /var/local/sumitty/instructors/valid
+   ls /home > /var/local/submitty/instructors/valid
    ```
 
 8. We recommend that you should leave the PostgreSQL setup unless you know what you're doing.
@@ -167,4 +167,4 @@ True
 
 If you get an error about module pam not being found, that means that `hwcgi` does not have the proper permissions to
 the module and if you get False on authentication, then `hwcgi` does not have the proper permissions to check the
-right files via PAM.
+right files via PAM.