Documentation request: Documentation for Analysis caching-related settings in the settings reference site

[mawright]

There are some settings in the "Analysis" subsection of the extension settings page that do not have descriptions in the Settings Reference page (https://code.visualstudio.com/docs/python/settings-reference).

In particular, I found that the settings "Caching Folder Path" and "Caching Level" don't have docs. This leads to some confusion: the "caching folder path" setting is blank by default - does this mean that there is no caching done, or that a default folder is used? The default setting for "caching level" is "Default," which is not very descriptive, and I'm unsure of the difference between the two other settings in the drop-down menu, "system" and "library."

[jakebailey]

This setting is an experimental feature that users aren't expected to change except for testing (it doesn't work entirely at the moment), hence the lack of documentation. Potentially, we should be removing them from the extension's info entirely until the feature is workable, though @karthiknadig this isn't something that we would do in this repo...