fix: update install suggestion for missing fyne command

[nobe4]

Description:

This makes the install process more inline with the CI workflow, where both are tested.

Checklist:

• Tests included. N/A: no test checked this string, so I didn't add one.
• Lint and formatter run with no errors.
• Tests all pass.

[andydotxyz]

Thanks for catching this. We don't need the "or go get" any more as the older way of installing binaries belongs to Go versions we don't support any more

[andydotxyz]

Great, thanks for this