Use furo theme for documentation
This MR updates the documentation to use the furo
HTML theme.
Maintenance will be performed on git.ligo.org, containers.ligo.org, and docs.ligo.org on Tuesday 2 July 2024 starting at approximately 9:30am PDT. It is expected to take around two hours and there will be several periods of downtime throughout the maintenance. Please address any comments, concerns, or questions to the helpdesk.
This MR updates the documentation to use the furo
HTML theme.