MDL-21695 adding help strings

lang/en/grades.php

@@ -285,6 +285,7 @@ $string['gradeitems'] = 'Grade items';
 $string['gradeitemsettings'] = 'Grade item settings';
 $string['gradeitemsinc'] = 'Grade items to be included';
 $string['gradeletter'] = 'Grade letter';
+$string['gradeletter_help'] = 'Grade letters are letters, A, B, C, ..., or words, for example Distinction, Merit, Pass, ..., used to represent a range of grades.';
 $string['gradeletterhelp'] = 'Grade letter Help';
 $string['gradeletternote'] = 'To delete a grade letter just empty any of the<br /> three text areas for that letter and click submit.';
 $string['gradeletters'] = 'Grade letters';
@@ -492,6 +493,7 @@ $string['overridden'] = 'Overridden';
 $string['overriddenhelp'] = 'When on, the overridden flag prevents any future attempts to automatically adjust the value of the grade. This flag is often set internally by the gradebook, but can be switched on and off manually using this form element.';
 $string['overriddennotice'] = 'Your final grade from this activity was manually adjusted.';
 $string['overridesitedefaultgradedisplaytype'] = 'Override site defaults';
+$string['overridesitedefaultgradedisplaytype_help'] = 'If ticked, grade letters and boundaries for the course may be set, rather than using the site defaults.';
 $string['overridesitedefaultgradedisplaytypehelp'] = 'Tick this checkbox to enable the overriding of the site defaults for the display of grades in the gradebook. This activates form elements allowing you to define the grade letters and boundaries of your choice.';
 $string['parentcategory'] = 'Parent category';
 $string['pctoftotalgrade'] = '% of total grade';