Nim RFCs are transferred from nim-lang/Nim repo to a new home:
https://github.com/nim-lang/RFCs
What this means is that you shouldn't open new issues in the main Nim repo to discuss your proposals for the language anymore.
The idea is to have a more formal way for proposing and discussing new features and/or language changes. The details are still in the works, but you can expect something PEP-like.
Until the details are defined and implemented, the best course of action would be to NOT submit any new RFCs - this will save both you and us some time. If you can't resist the urge to propose something, please write and save it locally on your computer. You can submit it later. Also, when opening an issue in the main repo, make sure it really is an issue and not a RFC in disguise.
I'll let you know when RFC repo is ready to use.