Add auto filters to spreadsheet

[apaleslimghost]

The spreadsheet could have auto filters on each column. This would make it more usable, especially once Domains are added (#8)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[rowanmanning]

Reopening, we probably should have disabled stale bot while we were on hiatus.