GitLab

Update README and version for v0.2 release.

Support `--host-list` for deploy and run commands.

Before this change, an inventory file is needed to use `sb deploy/run`.
Now, `--host-list localhost` or `-l localhost` is sufficient for quick try.

* Support custom output directory.
* Update document.

* Add introduction and release documents.
* Fix some typos in documents.

Update SuperBench documents.