Has functions to display different screens to the user of the cursive TUI.
Has functions used to serialize and deserialize the program state
Stores the State of the program and the user's data. Gets serialized after every change.
Stores the name of all the rust book chapters. The indexes of each chapter string are referenced throughout the program.
Used to find the index of a user-inputted chapter name in the
Finds the lowest ranked chapter and returns the an Option with the index of the chapter in the