[feature request] Allow to disable goal

[felicienfrancois]

Currently, there is no way to disable the goal and the associated count down in notification.

I would love to be able to disable it and simply have a count up in this text placeholder.

i.e. to replace "653 steps to go" by "347 steps today"

[felicienfrancois]

I found a hack: I set the Goal to 1 and put appropriate wordings.
It makes almost the job.
The only thing is the progress bar which is displayed while it does not makes sense in my case