Update how to use documentation on the site

[KCarlile]

Background

With recent changes to functionality (currently in develop branch), the how to use documentation on the home page and About page need to be updated.

Acceptance Criteria

• "How do I use Flash Chord?" help text is now updated to reflect the latest changes
• "Details" section of the About page is updated to reflect the latest changes
• Any issues on the FAQ page are addressed (added/edited/removed)

Approach

• Try out the new settings and features of Flash Chord
• Edit the documentation for how to use on the home and About pages
• Review the FAQ for any edits that need to be made