file system cache doc change

[MehulBatra]

Description

File system cache document change on optional fields

Additional context and related issues

As a developer when we try to enable caching, we face errors for setting options and try to look through it via logs what went wrong, if we could specify proactively that would make things easier.

Release notes

(*) This is not user-visible or is docs only, and no release notes are required. ( ) Release notes are required. Please propose a release note for me. ( ) Release notes are required, with the following suggested text:

# Section
* Fix some things. ({issue}`issuenumber`)