provide starting message for tar ball install

[stevenGravy]

On small machines like t2.nano the user may not see any output for 20-30 seconds after starting install. This gives a starting message while it's doing the copying.

New output with first line.

Starting Teleport installation...
Teleport binaries have been copied to /usr/local/bin

Thanks for installing Teleport.

Is it OK if we collect some info about your install?
Please run this command to send in a survey.
Optional: Replace email to join our newsletter and get a swag package.
$ curl -X POST https://usage.teleport.dev -F OS=linux -F use-case="access my ..." -F email="alice@example.com"

Otherwise, ignore

[public-teleport-github-review-bot]

@stevenGravy See the table below for backport results.

Branch	Result
branch/v11	Create PR
branch/v12	Create PR
branch/v13	Create PR