added remember me feature #53 (#98)

cleanup event subscriber

var/docs/users.md

@@ -2,7 +2,7 @@
 
 There are multiple pre-defined roles in Kimai, which define the ACLs. A user can only inherit one role, where the roles extend each user.
 
-## Roles
+## Roles & Permissions
 
 | Role name | extends | Gives permission for |
 |---|---|---|
@@ -12,3 +12,21 @@ There are multiple pre-defined roles in Kimai, which define the ACLs. A user can
 | ROLE_ADMIN | ROLE_TEAMLEAD | All of the above, plus: editing customers, editing projects, editing activities |
 | ROLE_SUPER_ADMIN | ROLE_ADMIN  | All of the above, plus: editing users  |
 
+# Login & Authentication
+
+- User can login with their username or email
+- If you activate the `Remember me` option, you can use use the most common functions within the next days without a new login
+
+## Remember me login
+
+If you have chosen to login with the `Remember me` option, your login will be extended to one week (default value).
+After coming back and being remembered you have access to all the following features: 
+- view your own timesheet
+- start and stop new records
+- edit existing records
+
+If you are an administrator, you will see all your allowed options in the menu, but will be redirected to the login 
+form when you try to access them. This is a security feature to prevent abuse in case you forgot to logout in public 
+environments.
+
+The default period for the `Remember me` option can be changed in the config file [security.yaml](config/packages/security.yaml).