1. Asks the user for their average grade (as a % out of 100) for each of the above grade categories
a. If there is no data for a category, the user should enter the value -1
i. In such cases, the total score used to calculate our average changes
2. After all categories have had information input, calculate the user’s class grade based on the syllabus values above. Display a percentage and letter grade to the user.
