launcher: Fix ambiguous token setup instructions

[kc9jud]

The previous instructions suggested that the token should be part of the command line arguments, while it should actually be passed as input.

[olivercalder]

Agreed. This confused me and I had to dig around to figure out how this was supposed to work.

On first run, we see:

A default configuration file has been created at
  /home/oac/snap/matterhorn/490/.config/matterhorn/config.ini

Use with your $EDITOR to customize it

Call this command to setup an access token:
  snap run --shell matterhorn -c \
    'secret-tool store --label="$SNAP_NAME" $SNAP_NAME <token>'

Press any key to run matterhorn...

The <token> should literally be called token, and the <token> should be pasted in when asked for a password.

I would suggest the help message say something like this instead:

A default configuration file has been created at
  /home/oac/snap/matterhorn/490/.config/matterhorn/config.ini

Use with your $EDITOR to customize it.

It is recommended to set a host URL and un-comment the `tokencmd` line once you have set an access token.

Call this command to setup an access token, and when asked for a password, paste the access token:
  snap run --shell matterhorn -c \
    'secret-tool store --label="$SNAP_NAME" $SNAP_NAME token'

Press any key to run matterhorn...