Add an About page to the calculator

[jasmith55]

Add a short description of the calculator at the top of the calculator page. For the description summarize what the calculator is for.
Here is a description from Francisco about why to use the tool:

Why use this tool?
This tool can aid school districts in interpreting and visualizing the benefits of investing in electric school buses. Not only can electric school buses provide kids with safer, more enjoyable rides to school, but they can also help school districts save money on fuel for their buses.

Annual electricity costs to charge an electric school bus can be much cheaper than fueling a diesel bus. However, there are many factors which may increase or decrease the electricity bill for charging electric school buses such as charging infrastructure, time of use, bus charge capacity, bus range, and bus route length.

This tool can be used to help school districts optimize electric school bus use by finding the best ways for them to save up to thousands of dollars on their school buses annually while ensuring these buses can fulfill their daily tasks.