Expose log files in iOS Files app

[ara4n]

It'd be helpful to expose EX's log files in the iOS Files app to help advanced users see what's going on when debugging, and to give confidence over what we log.

[stefanceriu]

Hi, we had a look at this but Element X is using an AppGroup to share log locations between different processes. The UISupportsDocumentBrowser Info.plist key only allows files that are present in the App's local Documents folder to be exposed to the Files.app. There are of course workarounds but none that are worth it in our oppinion. We would much rather just do #734