optionally support creation & completion dates

[jpouellet]

These are both parts of the Todo.txt format and documented here:

• creation dates
• completion dates

It would be nice to have an option to set these automatically (and perhaps another option to not display them)

I feel this is not really feature creep, since they are explicitly already part of the very minimal standard format and supported & used by other tools & people.

[jpouellet]

If I still use your app in a few weeks I'll probably implement this myself.

[JMoerman]

This has already been requested here: #55
Other than that I agree that it would indeed be nice to have that option.

[jpouellet]

Noted. Closing as duplicate.