fix the router

[ejkorol]

Overview

Using a basename with the hashrouter is problematic in this case because the deployed url is https://vltpkg.github.io/benchmarks/, however with the basename set to /benchmarks the actual url is https://vltpkg.github.io/benchmarks/#/benchmarks/ since the hashrouter will ignore everything up until the #

It also fixes the issue with loading the data that is prefixed with the date, instead just loads the chart data prefixed with /latest and removes the new Date() helpers in the constants dir.

This will work ontop of #19

Solution

Remove the basename from the createHashRouter call in routes.tsx
Update the data fetching to use the /latest prefix instead of the date prefix.