More informative download graphs

[allan2]

One of the most common tasks for a visitor who is looking up a package is to see its popularity over time.

The current versioned daily graphs are a bit "noisy" for this.

Compare these graphs for two packages growing in popularity:

Left: crates.io, daily data points.
Right: npmtrends.coms, weekly data points.

The right graph makes it easier to discern popularity over time, which is arguably the most common user task.

The left graph has versions and periodic "weekend dips" which are visually distracting from this task. While examining the adoption of versions over time is a useful feature, it may not be the best one to display as the default view.

Some suggestions for the download graph:

• be able to select the time period of the graph
  • currently, only viewing over the last 90 days is possible
  • suggested minimum: 1mo, 3mo, 6mo, 12mo, 1yr, 2yr, 5yr, all-time
  • even better: be able to specify a specific period (like Jan 1, 2022 to November 1, 2022)
• ability to select specific versions
  • currently, all versions are displayed*
  • suggested: allow specifying specific versions, with a cumulative view (summing all versions)
• ability to select data point frequency
  • currently, only viewing by daily is possible
  • suggested: allow browsing by weekly

I think weekly data points and cumulative-version graph are reasonable defaults, similar to how npmtrends does it.

#4336 related

Edit: * Referring to the crate page. It is possible to view a crate and its graph by version, e.g. https://crates.io/crates/rand/0.8.5