[Feature Request] Give advice on Activity length

[lorensr]

Is your feature request related to a problem? Please describe.

A couple users have been uncertain how much to put in a single Activity versus breaking it into multiple Activities.

Describe the solution you'd like

It would be helpful to have a concepts page/section on that architecture decision. The pros/cons of each, and example use cases.

Additional context

https://github.com/temporalio/documentation/pull/882#issuecomment-1035875835

[swyxio]

worth pointing to this as well https://github.com/andreasasprou/temporal-url-batch-scraping