Add a feature page for ALDashboard

[purplesky2016]

This repo's landing page doesn't have details.

1. Add a page to the doc site to explain "what this tool does and when to use what" would be helpful.
2. Add this doc page's link to that landing page will maintain its minimum text.

[purplesky2016]

Similarly, we may want to add a page for InterviewStats.

[nonprofittechy]

We have a stub for this right now in #564 but it should be updated to list all of the user-facing modules and what they do. It could be managed by editing the docstring for aldashboard.py.