The doc/api is a legacy name, which is confusing in the current use, since all build targets are now APIs.
Today we have:
doc/common: Common configuration and settings between all targets.
doc/main: Main Pybricks documentation at docs.pybricks.com.
doc/ide: Documentation shipped with the Pybricks Code IDE.
This removes versioneer for versioning. The version depends on the
pybricks-micropython version targeted so it doesn't make sense to use
automatic versioning here.