feat(Instagram): Change link sharing domain

[Julmik647]

Feature description

Currently this feature is in Twitter/X and some users requested to add it to Reddit and TikTok and I reccommend to add it to Instagram using Imginn. The link format here is https://imginn.com/p/(post ID) and https://imginn.com/(username).

Motivation

I think that Imginn is better for users that don't want to log in to Instagram account, so it can be better for sharing with friends that don't have Instagram.

Acknowledgements

• I have checked all open and closed feature requests and this is not a duplicate
• I have chosen an appropriate title.
• All requested information has been provided properly.