social media share links in various modals have been removed pending refactoring

[Alys]

As reported by @passocurto (eceb52cf-f4ad-457a-a0e1-265624812200):

"The link to share a new level on twitter is leading to an error page. When you try to access https://habitica.com/social/level-up you're redirected to the 404 not-found page: https://habitica.com/static/not-found

Edit by Alys 2021-08-31:

The staff decided to remove the share buttons until they have a chance to refactor the code (https://github.com/HabitRPG/habitica/pull/11536). I've labelled this as on hold.

This issue applies to multiple modals:

• level-up
• onboarding (the modals a new user sees)
• achievement gained
• challenge won
• contributor tier gained
• possibly others - any other modals that no longer have the share buttons are convered by this issue

[Alys]

This also applies to the modal you see when you gain a contributor tier. I'm adding that to the list in the top post and adjusting the title to make it more generic so it's more easily found.