version subcommand should show current cli version

Currently it looks like the version is hardcoded to dev ([here](https://github.com/chaoss/disclosure/blob/main/cmd/cmd.go#L26)). This should be updated to output current cli version.

Example for release 1.0.1:
```sh
$ disclosure version
v1.0.1
```

Start at cmd/cmd.go line 26, where the CLI version is currently hardcoded. Run the disclosure version subcommand and inspect how the release version is represented in the project. Done means a release such as 1.0.1 prints v1.0.1 instead of dev.

Written by the indexing model from the issue text.