Offset for timestamp command

[base-I]

Add functionality do define an offset for the timestamp command in settings. Usually a note is taken after a thought has been said - currently I have to skip back manually before adding the timestamp, which is somewhat cumbersome. Was not able to figure it out with moment.js/changing myself...

[Ton-yi]

I'm also having this problem,

I was just think of using a script by templater-plugin to fetch the numbers at the end(since it adjust the time)
and change them with a preset value (e.g -5)

I will be happy there's other solution or someone could teach me how to deal with moment in this usecase

[chhoumann]

Thank you for the feature suggestion! Added in #131