Review documentation in depth and modify as needed

[johnjasa]

The docs were kind of stitched together from a variety of ideas at different times. Go through these docs holistically and update / rearrange as necessary.

[ericmarc-aurele]

Using plot_wing requires sqlitedict library to be installed. Perhaps mention this in the installation documentation. (New to contributing on github, so if this should be somewhere else let me know)

[johnjasa]

Thanks, Eric! I've merged a fix to this just now. Sqlitedict is no longer needed, so I have removed all imports of it.

If you notice anything else, feel free to submit an issue or comment.