Generate the help pages using `cobras` builtin functionality and commit
them to the repository. This gives users to ability to review the
options of `hcloud-upload-image` without having to install it first.
The current setup of the CLI requires the user to set HCLOUD_TOKEN for
every single invocation of the binary. Even if we just want to
autocomplete some arguments or even generate the completion scripts in
CI.
This fixes the bug by only initializing the hcloud-go client in the
"cleanup" and "upload" subcommands.
