Update package overview

[lindeloev]

The overview should include the yet-to-be-reviewed/tested packages mentioned at the top, and perhaps an additional example: https://lindeloev.github.io/mcp/articles/packages.html.

Also update:

• strucchange::breakpoints does take time series and returns confidence intervals on the break points.
• changepoint.geo. It reduces multivariate problems to angle+length in vector space, and calls cpt.mean and cpt.var on this using PELT. So it's changepoint but with a tweak to allow for high-dimensional data.
• Searching for "change detection" yields a set of new packages, e.g., changedetection.