Fix documentation

Fix typos and improve documentation for "setup_group_settings_tabs",
"setup_operator_settings_tabs" and "setup_settings_tabs" functions.

src/mibew/libs/groups.php

@@ -40,11 +40,11 @@ function get_group_name($group)
 }
 
 /**
- * Builds list of group settings tabs. The keys are tabsa titles and the values
+ * Builds list of group settings tabs. The keys are tabs titles and the values
  * are tabs URLs.
  *
- * @param int $gid Group ID
- * @param int $active Number of the active tab.
+ * @param int $gid ID of the group whose settings page is displayed.
+ * @param int $active Number of the active tab. The count starts from 0.
  * @return array Tabs list
  */
 function setup_group_settings_tabs($gid, $active) {

src/mibew/libs/operator_settings.php

@@ -20,8 +20,9 @@
  * Builds list of operator settings tabs. The keys of the resulting array are
  * tabs titles and the values are tabs URLs.
  *
- * @param int $operator_id ID of the operator whose settings page uis displayed
- * @param int $active Number of the active tab
+ * @param int $operator_id ID of the operator whose settings page is displayed.
+ * @param int $active Number of the active tab. The count starts from 0.
+ * @return array Tabs list
  */
 function setup_operator_settings_tabs($operator_id, $active) {
 	$tabs = array();

src/mibew/libs/settings.php

@@ -22,7 +22,8 @@ use Mibew\Settings;
  * Builds list of the system settings tabs. The keys of the resulting array are
  * tabs titles and the values are tabs URLs.
  *
- * @param int $active Number of the active tab
+ * @param int $active Number of the active tab. The count starts from 0.
+ * @return array Tabs list
  */
 function setup_settings_tabs($active) {
 	$tabs = array(