typo

User-documentation.md

@@ -8,7 +8,7 @@
 - After successful registration you should be automatically logged in by web application.
 - Same as for registration there are two ways of login. Using built-in authentication or some external one.
 - During registration instance had to be chosen. After login you should see some information about joined instance and also public groups which are part of that instance.
-- Groups have some hierarchy which can be also observed in instance detail. You can join any group which is visible there, but there can also be private non-visible groups in which only supervisors can add members.
+- Groups have some hierarchy which can be also observed in instance detail. You can join any group which is visible there, but there can also be private non-visible groups to which only supervisors can add members.
 - After joining appropriate group there is dashboard where content of group can be seen. Most notably list of all public assigned exercises if there are any.
 - On assignment detail there can be found description of exercise, deadlines and some other information.
 - The most important thing to student in ReCodEx is "Submit new solution" button. After clicking on it you can upload all files which will be used on evaluation and then submit them.