spin up help woes again

[itowlson]

Using Spin 1.2 from the installer, in a directory without an application, spin up without any argument displays trigger options:

ivan@hecate:~/spinbin$ ./spin up
TRIGGER OPTIONS:
        --allow-transient-write
            Set the static assets of the components in the temporary directory as writable

        --cache <WASMTIME_CACHE_FILE>
            Wasmtime cache configuration file

            [env: WASMTIME_CACHE_FILE=]

# etc

It should display usage information or something like that.

(This goes back several versions. I am guessing I broke this when we switched to "unified -f" - I thought I had tested this case but clearly not!)