Add --version

[jayvdb]

--version is a cheap way to verify a binary is usable, and record in the logs which version was used, useful for detecting when a new release started causing a problem.

[jayvdb]

It appears there is a subcommand version. I believe --version is the expected way to get the version. See taiki-e/install-action#577

[jai-deepsource]

@jayvdb as you mentioned, you can use deepsource version which returns the currently installed version.