Update Documentation

[martinogarrizzo5]

Hi,
I recently implemented the plugin in 2 apps and I discovered this tricky mechanic of Apple.
To work the plugin needs to have the option "Copy only when installing" unchecked in the Xcode section "Build Phases > Embed Foundation Extensions". If it is checked the app will not show in the options when sharing a file.
Can you add it in the issues section of the documentation?
I think it will help many people in troubleshooting their app.
Thanks