Pulumi CLI dev builds should be documented in Troubleshooting

[jkodroff]

Using a dev release is helpful when working with Pulumi to debug issues, but we only not that dev builds exist in the blog, rather than the docs, the latter being the home for info that's useful in the long term.

Here's the blog post: https://www.pulumi.com/blog/introducing-dev-releases/

Here's where I think we should add the info: https://www.pulumi.com/docs/iac/support/troubleshooting/

[jkodroff]

Correction: It is documented, but it's here: https://www.pulumi.com/docs/iac/download-install/#installing-dev-releases

We should add a link from the Troubleshooting page to the authoritative content in Download/Install.