[README] Farmer's Delight Refabricated 1.21

[MerchantPug]

If you are using Farmer's Delight Refabricated 1.21...

You should not be reporting issues here, as we use a forked version. Porting Lib has not released for 1.21 yet, so you're ultimately just telling them things that they'll likely fix before a full release.

Please instead report to https://github.com/MehVahdJukaar/FarmersDelightRefabricated

This is our problem because we are using an early fork, not theirs.

please pin this PL devs, thanks