Just good first issues

This issue proposes renaming transfer definition extension files from `.conf` to `.transfer` to align with recent systemd-sysupdate changes (v257 and later). The user experienced a warning when following existing documentation and found that changing the file extension resolves the issue.

This issue proposes changes to the preferred labels and definitions of two XAS measurement modes to comply with established label rules. The current labels 'XAS Transmission' and 'XAS Fluorescence' will become alternate labels, with new preferred labels like 'transmission X-ray absorption spectroscopy' and 'fluorescence X-ray absorption spectroscopy'. The definitions will also be rephrased to better reflect their relationship as narrower concepts of X-ray absorption spectroscopy.

This issue proposes to correct a misspelling in the label 'voltammogramm' to 'voltammogram' and to change its parent concept from 'processes' to 'non-temporal abstract entity'. The change is justified because a graphical representation of results is not a process itself and no specific concept for data representations currently exists.

The `bootc-image-builder` project has been archived and development has moved to `osbuild/image-builder`. This issue highlights existing problems with the out-of-the-box experience and related VM functionality, indicating a need to address these issues in the new project.