Start 'cmdline/run' task in project directory.

By default 'cmdline/run' task is started in 'cmdline' directory,
so 'sbt cmdline/run batch svgs resources' command fails with
"svgs directory not found" error. The workaround was to use
'sbt cmdline/run batch ../svgs ../resources', but this fix is
better solution.
Fix instruction

Fix SBT plugin name in usage section. Tell that packages are now
published to Sonatype OSS repository.