The datadog-api-client-go packagesite page is... enormous. The raw HTML over the wire from the server is over 21MB, and rendering performance is abysmal. It can take up to 25 seconds for the page to become fully responsive to input. Obviously, this is an outlier package, but even given that, there seems like plenty of room here for performance work.
I fired up the Chrome performance tooling to see if there was something obvious:
Nearly all the time is spent in "Recalculate Style", presumably because the browser is constantly re-flowing the page as more and more HTML gets thrown at it?