Provide masks DDD and DDDD to print "Yesterday", "Today" or "Tomorrow".

[TalhaAwan]

• If the date belongs to yesterday, today or tomorrow the masks should print so.
• If the date does not lie in these days then DDD should fall back to ddd and DDDD to dddd.
• Unit tests added
• Readme updated

[TalhaAwan]

Though tests are passing, the logic is incorrect. I mistakenly used day of week instead of day of month. Even with day of month, boundary conditions on changing months and years will need to be handled. Will try to work on this later.

[TalhaAwan]

Fixed with simplified logic.

[chase-manning]

@TalhaAwan Thanks so much for this PR, is a great idea!!!
Sorry this was not merged sooner, this repo was not under active maintenance at the time.
I would love to merge this PR but it has merge conflicts at the moment.
Would you be able to please fix the merge conflicts so I can merge this?

[chase-manning]

Thanks so much for the PR!!!
I have added some review comments to be resolved.

[TalhaAwan]

@chase-manning I resolved the readme conflicts only to find out that tests are not passing. Lots have changed since I opened this PR, so I'll have to re-add this functionality. Will do that soon.

[chase-manning]

Looks great!!! ❤️

[TalhaAwan]

@chase-manning "Yes", "Tom" and "Tod" look odd though. Do you think we should change that? I was looking it up and YDA, TDA, and TMW/TMR are the abbreviations that are used in certain fields. Let me know if this needs change.