How to interpret download stats

[kirbyju]

Could you potentially add a bit more detail to the https://github.com/Slicer/SlicerDeveloperToolsForExtensions/blob/master/README.md to help extension developers understand how to interpret the download stats?

E.g. with this sample output,

What is the difference between 5.2.2 and post-5.2.2? Does that mean we had 409 installs when 5.2.2 was the newest release available and then another 423 installs by 5.2.2 users after some newer version of Slicer was released? So if someone that's still using v5.2.2 installed our extension tomorrow that would change it to 424 in the post-5.2.2 column?

p.s. Thanks for setting this up so that we can track these stats!