Is your feature request related to a problem? Please describe.

Pyleoclim has so far focused on the recent past, but does not provide geologic context for timeseries fluctuations. This is problematic for Cenozoic-scale (or deeper-time) climate change -- essentially, anything before the Pleistocene.

Describe the solution you'd like
Add geologic timescale annotations at the bottom (optional: top) of timeseries plots. @PaleoLipidRR has some great code to do so, which could be repurposed here.

Describe alternatives you've considered
Keep ignoring the geologic timescale...