Navigation Drawer

[philipye314]

Todo:

• This will be a pretty complex task, but we'll be building the drawer navigator for the HFH guide. Look into react-native-drawer-navigation for how to do this - you're welcome to use other libraries if you see fit!
• Each Chapter when clicked on should expand and dropdown to reveal subheadings/subsections within the chapter. Clicking on one of these will scroll down to that section. Look into react-native's FlatList, especially the function scrollToIndex (edit: Look into both ScrollView and FlatList, and try to decide which is suitable)

Useful Links:

https://reactnavigation.org/docs/drawer-navigator/
https://reactnative.dev/docs/flatlist#scrolltoindex