CLI install instructions: duplicate link to releases and outdated version

[porridge]

Which page is affected?:

https://kudo.dev/docs/cli.html#setup-the-kudo-kubectl-plugin

It lists 4 ways to install CLI:

1. download from releases page (with a link)
2. use brew
3. use krew
4. download from releases page again but this time:

• with a non-clickable link,
• with a shell snippet with an old version string

What exactly is broken?:

• "downloading from releases page" is listed twice
• the URL should be clickable
• we could additionally or alternatively link to http://github.com/kudobuilder/kudo/releases/latest which redirects to latest non-RC
• we should think about what to do with the hardcoded version. Apparently this makes users think that this is the recommended version so we should either keep it up-to-date at all times, or replace it with something like vx.y.z to force users to pick one