Pit of Failure in Try Aspire flow - doesn't tell you how to install the aspire cli.

[afscrome]

Assume I'm a person new to aspire, who's never used it before

1. Go to https://aspire.dev/
2. Hit the "Try Aspire" button in the top right

The first instruction on that page is to run aspire new, but I haven't yet been told how to install the Aspire CLI.

If this pages uses the aspire cli for insturctions, it should also document how to get the aspire cli.

[alistairmatthews]

Good call. Thanks @afscrome. #1339 fixes this issue by linking to the prereqs in prominent notes before they run aspire new.