* chore(gschema-overrides): Get rid of `files` module dependency
Gschema.override files are now placed in /config/gschema-override folder.
* chore(gschema-overrides): Don't use 1st slash for new override location in docs
* chore: Use `zz1-` prefix instead of `z1-`
It ensures that no gschema override will bypass user one with override starting with letter z.