typo fix

doc/configure.md

doc/disable.md

doc/enable.md

doc/halt.md

doc/index.md

doc/init.md

doc/module-usage.md

doc/parse.md

doc/poweroff.md

doc/reboot.md

doc/reconfigure.md

doc/reload.md

doc/remove.md

doc/resolve.md

doc/restart.md

doc/scandir.md

doc/signal.md

doc/start.md

doc/state.md

doc/status.md