Replace "gc" with "rebuild" in man page. Also, explain IDs in the context of the working set of tasks.
Documentation
This directory contains Taskwarrior documentation that is built and installed along with the executable:
mancontains the source for the Taskwarrior manual pages.rccontains rcfiles that will be installed in/usr/share/doc/task/rcor equivalent.refcontains reference documentation that will be installed in/usr/share/doc/taskor equivalent.
It also contains developer documentation with a high-level view of how Taskwarrior development is done and how the pieces of the system fit together.