Introduce `DEBIAN_SUITE` as a configurable argument in the Dockerfile, build
script, and CI workflow to align kernel builds with the target Raspberry Pi
OS release. Updated documentation to clarify the relationship between
suite versions and kernel compatibility.
Expand the documentation to include details on GPIO descriptor
lookup using chip label and hardware offset, replacing the deprecated
global GPIO number approach. Added instructions for verifying the module's
version magic to ensure compatibility with the running kernel. These
updates aim to prevent common initialization and deployment errors.
